Effects of Dietary Changes on the Gut Microbiota of Cynops orientalis

The gut microbiota plays a pivotal role in the maintenance of health for amphibians,and it has been fully recognized,but the effectiveness of various influencing factors has not yet been fully clarified.Although this association should be considered while the amphibian order Caudata is facing a severe situation of population decline and extinction,there is little understanding of the association between diets and the diversity of gut microbiota in the amphibian order Caudata.Here,we conducted an extensive analysis of the gut microbiota of Cynops orientalis fed different diets using functional prediction and 16S rRNA amplicon sequencing techniques.First,we found that wild individuals had greater gut microbial diversity and richness in comparison to captive individuals.Second,we identified the bacterial taxa associated with diets and observed differences in the relative abundance of gut microbiota among people on various diets.Finally,we have a predictive comprehension of the selection and adaptative significance of shared core ASVs in the gut microbiota in maintaining the healthy survival of C.orientalis in a large-scale spatiotemporal map.Our study emphasizes how diets alter the gut microbiota of Caudata and offers fresh perspectives on the conservation and captive management of species in Caudata.

Diet and physical activity influence the composition of gut microbiota,benefit on Alzheimer's disease

Alzheimer's disease is a neurodegenerative disease with complex etiology.Gut microbiota influences the gutbrain axis,which may affect pathways related to the pathogenesis of Alzheimer's disease.Additionally,diet and physical activity are likely to affect the pathology of Alzheimer's disease as well as the gut microbiota.This demonstrates that it may be possible to prevent or halt the progression of Alzheimer's disease by regulating the gut microbiota using diet and physical activity strategies.Therefore,the present study reviews the association between these two interventions and gut microbiota in the human body.It also summarizes how these two interventions benefit Alzheimer's disease.Furthermore,the primary limitations of these two interventions are discussed and promising strategies are proposed,which may be beneficial to further study and develop the intervening measure for the progression of Alzheimer's disease.

Interaction between diet and genetics in patients with inflammatory bowel disease

In this editorial,we comment on the article by Marangoni et al,published in the recent issue of the World Journal of Gastroenterology 2023;29:5618-5629,about“Diet as an epigenetic factor in inflammatory bowel disease”.The authors emphasized the role of diet,especially the interaction with genetics,in promoting the inflam-matory process in inflammatory bowel disease(IBD)patients,focusing on DNA methylation,histone modifications,and the influence of microRNAs.In this editorial,we explore the interaction between genetics,gut microbiota,and diet,in an only way.Furthermore,we provided dietary recommendations for patients with IBD.The Western diet,characterized by a low fiber content and deficiency the micronutrients,impacts short-chain fatty acids production and may be related to the pathogenesis of IBD.On the other hand,the consumption of the Mediter-ranean diet and dietary fibers are associated with reduced risk of IBD flares,particularly in Crohn’s disease(CD)patients.According to the dietary guidance from the International Organization for the Study of Inflammatory Bowel Diseases(IOIBD),the regular consumption of fruits and vegetables while reducing the consumption of saturated,trans,dairy fat,additives,processed foods rich in maltodextrins,and artificial sweeteners containing sucralose or saccharine is recommended to CD patients.For patients with ulcerative colitis,the IOIBD recommends the increased intake of natural sources of omega-3 fatty acids and follows the same restrictive recommendations aimed at CD patients,with the possible inclusion of red meats.In conclusion,IBD is a complex and hetero-geneous disease,and future studies are needed to elucidate the influence of epigenetics on diet and microbiota in IBD patients.

Global research trends on diet and nutrition in Crohn’s disease

BACKGROUND Crohn’s disease represents a challenge for patients concerned with the modified diet regimen as well as practitioners who seek the best nutritional therapy.Crohn’s disease can alter the body’s ability to digest food and to absorb nutrients,resulting in severe vitamin deficiencies,malnutrition and sometimes lifethreatening complications.However,a comprehensive bibliometric analysis is lacking to map the current links between nutrition and Crohn’s disease in terms of the number of citations,geographic distribution and growth trends of publications.AIM To introduce the current state of research as well as hotspots in the field of nutrition and Crohn’s disease from a bibliometric standpoint.METHODS We searched the Scopus database and selected the relevant literature on nutrition and Crohn’s disease that met the inclusion criteria.We analyzed the publication trends and research hotspots by using video object segmentation viewer software.RESULTS We included 1237 publications.The number of documents published each year has increased steadily.The United States and the University of Otago,Christchurch,have had the highest productivity,with 208(16.81%)and 29(2.34%)documents,respectively.The“role of exclusive enteral nutrition for complicated Crohn’s disease”and“manipulation of the gut microbiota as a key target for Crohn’s disease”were the major research areas in 2016-2021,and they could be extensively investigated in the future.Meanwhile,research on“malnutrition in patients with Crohn’s disease”appeared to be an area that attracted more research attention before 2016.CONCLUSION This is the first bibliometric analysis to map the knowledge structure and trends regarding nutrition in Crohn’s disease research over the past two decades.The results provide a comprehensive summary and identification of the frontiers of nutrition and Crohn’s disease-related research,which may be used as a resource by researchers in the field.

Selecting the best:Interspecific and age-related diet differences among sympatric steppe passerines

Parental food provisioning is crucial for the growth and survival of offspring.Growth rate depends on food quality and food supplied to offspring may differ from what adults use for their own.In the case of steppe passerine birds,detailed characterization on nestling dietary composition,as well as prey choice and resource partitioning among species,is a pending subject.Dietary differences between nestlings and adults remain also largely unexplored.By using faecal DNA metabarcoding,we described the diet of nestlings and adults of five shrub-steppe passerine species over the 2017–2019 breeding seasons in central Spain.We also monitored arthropod availability in the field to assess dietary selection.We expected interspecific dietary differences to limit competition for food resources among sympatric species,as well as parental selection of high quality prey for nestlings.We also predicted age-related differences,with nestlings being fed nutrient-rich prey more frequently than adults.The main arthropod orders provisioned to nestlings were Orthoptera,Julida,Araneae and Lepidoptera.Nestlings of the different species showed high interspecific diet overlap,indicating both a coincidence in growth needs among bird species and no or little limitation of the most profitable resources during the breeding season.Adults of all species showed higher diet richness than nestlings,and age-related differences in prey composition were mainly driven by the selection of the most easily digestible,larger protein-and calcium-rich prey for nestlings,which may favour their rapid growth,and avoiding highly sclerotized and less nutritional prey such as ants.Our study sheds light on the basic ecology and conservation of these declining steppe birds,indicating that interspecific competition may not be a major factor during the breeding season.Given the current global decline of arthropods,further long-term research would be necessary,along with the implementation of effective conservation measures that ensure a sufficient availability of resources identified as key prey in the diet of steppe bird nestlings.

基于Swanson关怀理论的护理干预在早产儿母亲中的应用

目的:探讨以Swanson关怀理论为框架的护理干预在早产儿母亲中的应用效果。方法:采取便利抽样法选取2022年1月-5月入住百色市某三级甲等医院新生儿重症监护室(NICU)治愈出院的40例早产儿母亲作为对照组,选取2022年6月-10月入住百色市某三级甲等医院NICU治愈出院的40例早产儿母亲作为试验组。对照组实施NICU常规护理,试验组在对照组干预的基础上实施基于Swanson关怀理论的护理干预,比较两组早产儿母亲干预前后疾病不确定感、希望水平、育儿胜任感得分情况。结果:干预后试验组早产儿母亲疾病不确定感得分明显低于对照组(P<0.001),希望水平得分明显高于对照组(P<0.001);出院时及出院1个月后试验组早产儿母亲育儿胜任感得分明显高于对照组(P<0.001)。结论:基于Swanson关怀理论的护理干预可有效降低早产儿母亲疾病不确定感水平,提高其希望水平,增强其育儿胜任感,有利于早产儿顺利从医院过渡至家庭。

Role of diet in the management of inflammatory bowel disease

Many studies have looked at connections between diet,etiology,signs and symptoms associated with inflammatory bowel disease(IBD).Although these connections are apparent to clinicians,they are difficult to prove qualitatively or quantitatively.Enteral feeding and polymeric diets are equally effective at bringing about remission in Crohn's disease(CD).Parenteral feeding is also effective,although none of these methods is as effective as corticosteroid therapy.However,enteral feeding is preferred in the pediatric population because linear growth is more adequately maintained via this route.Exclusion diets in patients brought into remission using an elemental diet have been shown to maintain remission for longer periods.Studies that aim to isolate culpable food groups have shown that individuals react differently on exposure to or exclusion of various foods.The commonly identifi ed food sensitivities are cereals,milk,eggs,vegetables and citrus fruits.Studies that have looked at gut mucosal antigen behavior have shown higher rectal blood flow,in response to specifi c food antigens,in those with CD over healthy subjects.Exclusion of sugar shows little evidence of amelioration in CD.Omega 3 fatty acids show promise in the treatment of IBD but await larger randomized controlled trials.Patients frequently notice that specifi c foods cause aggravation of their symptoms.Whilst it has been diffi cult to pinpoint specifi c foods,with advances in the laboratory tests and food supplements available,the aim is to prolong remission in these patients using dietary measures,and reduce the need for pharmacotherapy and surgical intervention.

Diet and microbiota in inflammatory bowel disease: The gut in disharmony

Bacterial colonization of the gut shapes both the local and the systemic immune response and is implicated in the modulation of immunity in both healthy and disease states. Recently, quantitative and qualitative changes in the composition of the gut microbiota have been detected in Crohn's disease and ulcerative colitis, reinforcing the hypothesis of dysbiosis as a relevant mechanism underlying inflammatory bowel disease(IBD) pathogenesis. Humans and microbes have coexisted and co-evolved for a long time in a mutually beneficial symbiotic association essential for maintaining homeostasis. However, the microbiome is dynamic, changing with age and in response to environmental modifications. Among such environmental factors, food and alimentary habits, progressively altered in modern societies, appear to be critical modulators of the microbiota, contributing to or co-participating in dysbiosis. In addition, food constituents such as micronutrients are important regulators of mucosal immunity, with direct or indirect effects on the gut microbiota. Moreover, food constituents have recently been shown to modulate epigenetic mechanisms, which can result in increased risk for the development and progression of IBD. Therefore, it is likely that a better understanding of the role of different food components in intestinal homeostasis and the resident microbiota will be essential for unravelling the complex molecular basis of the epigenetic, genetic and environment interactions underlying IBD pathogenesis as well as for offering dietary interventions with minimal side effects.

Lifestyle-related disease in Crohn’s disease: Relapse prevention by a semi-vegetarian diet

AIM: To investigate whether semi-vegetarian diet (SVD) has a preventive effect against relapse of Crohn’s disease (CD) in patients who have achieved remission,who are a high-risk group for relapse.METHODS: A prospective,single center,2-year clinical trial was conducted.Twenty-two adult CD patients who achieved clinical remission either medically (n = 17) or surgically (n = 5) and consumed an SVD during hospitalization were advised to continue with an SVD and avoid known high-risk foods for inflammatory bowel disease.The primary endpoint was clinical relapse defi ned as the appearance of active symptoms of CD.Kaplan-Meier survival analysis was used to calculate the cumulative proportion of patients who had a relapse.A 2-year analysis of relapse rates of patients who followed an SVD and those who did not (an omnivorous diet group) was undertaken.RESULTS: SVD was continued by 16 patients (compliance 73%).Remission was maintained in 15 of 16 patients (94%) in the SVD group vs two of six (33%)in the omnivorous group.Remission rate with SVD was 100% at 1 year and 92% at 2 years.SVD showed signif icant prevention in the time to relapse compared to that in the omnivorous group (P = 0.0003,log rank test).The concentration of C-reactive protein was normal at the f inal visit in more than half of the patients in remission who were taking an SVD,who maintained remission during the study (9/15;60%),who terminated follow-up (8/12;67%),and who completed 2 years follow-up (7/10;70%).There was no untoward effect of SVD.CONCLUSION: SVD was highly effective in preventing relapse in CD.

Calorie restriction or dietary restriction: how far they can protect the brain against neurodegenerative diseases?

Finding the correct nutritional intervention is one of the biggest challenges in treating patients with neurodegenerative diseases.In general,these patients develop strong metabolic alterations,resulting in lower treatment efficacy and higher mortality rates.However,there are still many open questions regarding the effectiveness of dietary interventions in neurodiseases.Some studies have shown that a reduction in calorie intake activates key pathways that might be important for preventing or slowing down the progression of such diseases.However,it is still unclear whether these neuroprotective effects are associated with an overall reduction in calories(hypocaloric diet)or a specific nutrient restriction(diet restriction).Therefore,here we discuss how commonly or differently hypocaloric and restricted diets modulate signaling pathways and how these changes can protect the brain against neurodegenerative diseases.

Diet and medical foods in Parkinson’s disease

Parkinson’s disease (PD) is a slowly progressive neurodegenerative disorder with motor and non-motorsigns, which begins long before the diagnosis can be made. Pharmacotherapy with dopaminergic drugsis the mainstay of PD therapy. There is no currently available cure or disease-modifying treatment. Dietand various foods have been proposed as possible risk factors for PD. Nutritional supplementation withomega-3 fatty acids, vitamin D, B vitamins, and coenzyme Q may have potential in the management ofPD. In addition, several strategies could possibly lead to the development of medical foods in PD. Forexample, ketogenic diets may have effects complementary to pharmacotherapy. Gut microbial dysbiosisand altered microbial metabolites found in PD may lead to chronic low-grade inflammation in gut andbrain. Interventions targeting gut microbiota, such as the supplementation of probiotics, may providenovel approaches to PD in regard to both symptomatic treatment and disease modification. High qualityrandomized controlled trials need to be conducted in order to evaluate whether these food-basedstrategies have symptomatic efficacy or the potential to delay the progression of PD.

Acute duodenal Crohn's disease successfully managed with low-speed elemental diet infusion via nasogastric tube:A case report

Duodenal Crohn＇s disease is rare, and patients without obstruction are treated medically. We herein report one case whose duodenal Crohn＇s disease was successfully managed with low-speed elemental diet infusion through a nasogastric tube. A 28-year-old female developed acute duodenal Crohn＇s disease. Upper GI radiologic and endoscopic examinations showed a stricture in the duodenal bulb. Using the duodenal biopsy specimens, mucosal cytokine levels were measured; interleukin （IL）-1β, IL-6, IL-8, and tumor necrosis factor-α levels were remarkably elevated. For initial 2 wk, powdered mesalazine was orally given but it was not effective. For the next 2 wk, she was treated with low-speed elemental diet therapy using a commercially available ElentalTM, which was infused continuously through a nasogastric tube using an infusion pump. The tip of the nasogastric tube was placed at an immediate oral side of the pylorus. The infusion speed was 10 mL/h （usual speed, 100 mL/h）. After the 2-wk treatment, her symptoms were very much improved, and endoscopically, the duodenal stricture and inflammation improved. The duodenal mucosal cytokine levels remarkably decreased compared with those before the treatment. Although our experience was limited, lowspeed elemental diet infusion through a nasogastric tube may be a useful treatment for acute duodenal Crohn＇s disease.

Physical Activity, Mediterranean Diet and Biomarkers-Assessed Risk of Alzheimer’s: A Multi-Modality Brain Imaging Study

Increased physical activity and higher adherence to a Mediterranean-type diet (MeDi) have been independently associated with reduced risk of Alzheimer’s disease (AD). Their association has not been investigated with the use of biomarkers. This study examines whether, among cognitively normal (NL) individuals, those who are less physically active and show lower MeDi adherence have brain biomarker abnormalities consistent with AD. Methods: Forty-five NL individuals (age 54 ± 11, 71% women) with complete leisure time physical activity (LTA), dietary information, and cross-sectional 3D T1-weigthed MRI, 11C-Pittsburgh Compound B (PiB) and 18F-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) scans were examined. Voxel-wise multivariate partial least square (PLS) regression was used to examine the effects of LTA, MeDi and their interaction on brain biomarkers. Age, gender, ethnicity, education, caloric intake, BMI, family history of AD, Apolipoprotein E (APOE) genotype, presence of hypertension and insulin resistance were examined as confounds. Subjects were dichotomized into more and less physically active (LTA+ vs. LTA-;n = 21 vs. 24), and into higher vs. lower MeDi adherence groups (n = 18 vs. 27) using published scoring methods. Spatial patterns of brain biomarkers that represented the optimal association between the images and the groups were generated for all modalities using voxel-wise multivariate Partial Least Squares (PLS) regression. Results: Groups were comparable for clinical and neuropsychological measures. Independent effects of LTA and MeDi factors were observed in AD-vulnerable brain regions for all modalities (p β load and lower glucose metabolism) were observed in LTA- compared to LTA+ subjects, and in MeDi- as compared to MeDi+ subjects. A gradient effect was observed for all modalities so that LTA+/MeDi+ subjects had the highest and LTA+/MeDi+ subjects had the lowest AD-burden (p < 0.001), although the LTA × MeDi interaction was significant only for FDG measures (p < 0.03). Adjusting for covariates did not attenuate these relationships. Conclusion: Lower physical activity and MeDi adherence were associated with increased brain AD-burden among NL individuals, in-dicating that lifestyle factors may modulate AD risk. Studies with larger samples and longitudinal evaluations are needed to determine the predictive power of the observed associations.

Logical hypothesis:Low FODMAP diet to prevent diverticulitis

Despite little evidence for the therapeutic benefits of a high-fiber diet for diverticulitis, it is commonly recommended as part of the clinical management. The ongoing uncertainty of the cause(s) of diverticulitis confounds attempts to determine the validity of this therapy. However, the features of a high-fiber diet represent a logical contradiction for colon diverticulitis. Considering that Bernoulli&rsquo;s principle, by which enlarged diameter of the lumen leads to increased pressure and decreased fluid velocity, might contribute to development of the diverticulum. Thus, theoretically, prevention of high pressure in the colon would be important and adoption of a low FODMAP diet (consisting of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) may help prevent recurrence of diverticulitis.

In situ diet of the copepod Calanus sinicus in coastal waters of the South Yellow Sea and the Bohai Sea

Copepods are a key trophic link between primary producers and predatory animals at higher trophic levels in the marine ecosystem. Knowledge of the in situ composition of the copepod diet is critical for the accurate evaluation of trophic relationships and energy transfer in marine food webs. In this study, we applied a PCR-based cloning technique developed previously to investigate the in situ diet of Calanus sinicus, an ecologically important largesized calanoid copepod that dominates in the shelf waters around China, Japan and Korea. Analyses of the 18S rDNA sequences obtained from the copepod diet revealed the diverse food composition of C. sinicus from two stations （Y19 in the South Yellow Sea and B49 in the Bohai Sea）. A total of 43 operational taxonomic units （OTUs） were detected, which belonged to 13 diverse lineages： Bacillariophyta, Dinoflagellata, Dictyochophyceae, Chrysophyta, Katablepharidophyta, Pelagophyceae, Apusozoa, Hydrozoa, Ctenophora, Echinodermata, Tunicata, Chaetognatha and marine fungi. The results indicate that during an algae bloom, C. sinicus can graze on the bloom causative species. When the abundance of phytoplankton in ambient water is relatively low, C. sinicus can choose eggs, larvae, or organic particles/detritus of various metazoans, especially hydrozoans and ctenophores, as alternative food sources. Our result suggests that C. sinicus is an omnivorous species, and its prey choice may depend on the food availability in the ambient waters.

Role of diet and nutrition in inflammatory bowel disease

Inflammatory bowel diseases(IBDs)are closely linked to nutrition.The latest research indicates that diet and nutrition are significantly involved in the etiopathogenesis of the disease,although their specific role throughout its clinical course still remains unclear.This study reviewed how diet and nutrition are associated with IBD development and management.Even though specific diets have been shown to bring about positive outcomes,there is currently no scientific consensus regarding an appropriate diet that would benefit all IBD patients.We suggest that individualized dietary recommendations are of the greatest importance and that diets should be planned to provide individual IBD patients with specific nutrient requirements while keeping all the clinical aspects of the patients in mind.Further research is clearly necessary to investigate nutritional factors involved in IBD development and,especially,to evaluate the applications of the diets during the course of the disease.

Ketogenic diets and Alzheimer’s disease

Alzheimer’s disease(AD)is a progressive neurodegenerative disorder characterized by decline in cognitive functions and associated with the neuropathological hallmarks of amyloid-peptide plaques and neurofibrillary tangles.Cerebral glucose uptake and metabolism deteriorate in AD and this hypometabolism precedes the onset of clinical signs in AD.The early decline in brain glucose metabolism in AD has become a potential target for therapeutic intervention.This has led to investigations assessing the supplementation of the normal glucose supply with ketone bodies which are produced by the body during glucose deprivation and can be metabolized by the brain when glucose utilization is impaired.The present review provides a synopsis of preclinical studies and clinical trials assessing the efficacy of ketogenic diets in the treatment of AD.Both the direct administration of ketone bodies and the use of high-fat,low-carbohydrate ketogenic diets have been shown to be efficacious in animal models of AD and clinical trials with AD patients.The mechanism underlying the efficacy of ketogenic diets remains unclear,but some evidence points to the normalization of aberrant energy metabolism.At present there is only limited evidence of the usefulness of ketogenic diets in AD.However,this dietary approach seems to be promising and deserves further clinical investigations.

Mothers’ Knowledge of Health Caring for Premature Infants after Discharge from Neonatal Intensive Care Units in the Gaza Strip, Palestine

Background: Preterm labor is one of the most public health problems related to neonates admitted to Neonatal Intensive Care Unit (NICU). Poor knowledge among mothers about the care requirements of a preterm neonate is immediate cause for post-discharge medical problems in premature and neonates readmission to NICU. Hence, this study aims to evaluate mothers’ knowledge of caring for premature infants post-discharge from Neonatal Intensive Care Units in the Gaza strip. Methods: A Quantitative-based cross-sectional designs study was used to survey 120 mothers of preterm neonates at the time of preterm neonates discharge by face-to-face interview at Al-Shifa medical complex and Nasser hospital between February and June 2018. Results: The results showed that only about 58.4% of mothers of premature babies had good knowledge about health care needed for premature infants after discharge from NICU. Furthermore, there was no statistically significant difference between the level of knowledge and mother’s sociodemographic characteristics (P-values > 0.05). Conclusion: Mothers’ knowledge of premature infants care was not at the optimal level, which might put the newborns at risk. Therefore, the study emphasizes the necessity of thoughtful exchange of health information between team members and mothers and establishing pre- and post-discharge plans with mothers to start their healthy transition of preterm neonate to home and to ameliorate family concerns.

Crohn’s disease: Why the ileum?

Crohn’s disease(CD)is an inflammatory bowel disease characterized by immunemediated flares affecting any region of the intestine alternating with remission periods.In CD,the ileum is frequently affected and about one third of patients presents with a pure ileal type.Moreover,the ileal type of CD presents epidemiological specificities like a younger age at onset and often a strong link with smoking and genetic susceptibility genes.Most of these genes are associated with Paneth cell dysfunction,a cell type found in the intestinal crypts of the ileum.Besides,a Western-type diet is associated in epidemiological studies with CD onset and increasing evidence shows that diet can modulate the composition of bile acids and gut microbiota,which in turn modulates the susceptibility of the ileum to inflammation.Thus,the interplay between environmental factors and the histological and anatomical features of the ileum is thought to explain the specific transcriptome profile observed in CD ileitis.Indeed,both immune response and cellular healing processes harbour differences between ileal and non-ileal CD.Taken together,these findings advocate for a dedicated therapeutic approach to managing ileal CD.Currently,interventional pharmacological studies have failed to clearly demonstrate distinct response profiles according to disease site.However,the high rate of stricturing disease in ileal CD requires the identification of new therapeutic targets to significantly change the natural history of this debilitating disease.

Effect of high cholesterol diet on spatial learning and memory in a rat model of Alzheimer’s disease

BACKGROUND： Recently study indicates a potentially important link between cholesterol, Aβ deposit, and clinicopathological manifestation of Alzheimer＇s disease （AD）. OBJECTIVE： To study the effect of high cholesterol diet on cognitive function and neuronal loss of hippocampal dentate gyrus in AD model rats. DESIGN, TIME AND SETTING： A randomized controlled animal study, which was performed in the Laboratory of Stem Cells, Department of Pathology, Third Military Medical University of Chinese PLA from February 2006 to March 2007. MATERIALS： Twenty healthy, male, Wistar rats, aged 3-4 months and weighing （300 ± 20） g, were selected for this study. A β 1- 40 was provided by Sigma Company, USA. Standard diet and high cholesterol diet mixed with cholesterol （5%）, sodium hypocholic acid （1%）, lard （10%）, and ordinary rat food （84%） were provided by Experimental Animal Center, Institute of Field Surgery, Daping Hospital, Third Military Medical University of Chinese PLA. METHODS： Rats were fed on high cholesterol diet or standard diet for eight successive weeks. Then, rats were randomly divided into cholesterol diet ＋A β, high cholesterol diet ＋ phosphate buffered saline（PBS）, standard diet ＋ A β, and standard diet ＋ PBS group, with five rats in each group. AD rat models were established by local injection of A β 1-40 solution （10 μ L） into the hippocampal dentate gyrus. Rats in the control group were injected with the same volume of PBS. After injection, rat were fed for two weeks MAIN OUTCOME MEASURES： Neuronal cells in the hippocampal dentate gyrus were detected by Nissl staining; spatial navigation and spatial probe were detected by Morris water maze to reflect learning and memory. RESULTS： Twenty rats were included in the final analysis, without any loss. （1） Neuronal numbers： neuronal loss in the high cholesterol diet ＋ A β and standard diet ＋ A β groups was significantly higher than in the PBS groups （P 〈 0.01）. In particular, loss of pyramidal cells in the high cholesterol diet ＋ A β group was significantly higher than in the standard diet ＋ A β group （P 〈 0.01）. （2） Average escape latency： average escape latency was ranked as follows： cholesterol diet ＋ A β group 〉 standard diet ＋ A β group 〉 high cholesterol diet ＋ PBS group 〉 standard diet ＋ PBS group. Moreover, the number of occasions on which the platform was passed--as well as percentage of swimming distance between two quadrants within two minutes--negatively correlated with average escape latency. CONCLUSION： High cholesterol diet may accelerate neuronal loss in the hippocampal dentate gyrus and aggravate cognitive impairment in AD rats.