Comparative genomic analysis revealed that dietary habits affected the adaptation of Bifidobacterium bifidum to the intestinal tract in different geographic populations

Recent research on the genome of Bifidobacterium bifidum has mainly focused on the isolation sources(intestinal tract niche)recently,but reports on the isolation region are limited.This study analyzed the differences in the genome of B.bifidum isolated from different geographical populations by comparative genomic analysis.Results at the genome level indicated that the GC content of American isolates was significantly higher than that of Chinese and Russian isolates.The phylogenetic tree,based on 919 core genes showed that B.bifidum might be related to the geographical characteristics of isolation region.Furthermore,functional annotation analysis demonstrated that copy numbers of carbohydrate-active enzymes(CAZys)involved in the degradation of polysaccharide from plant and host sources in B.bifidum were high,and 18 CAZys showed significant differences across different geographical populations,indicating that B.bifidum had adapted to the human intestinal environment,especially in the groups with diets rich in fiber.Dietary habits were one of the main reasons for the differences of B.bifidum across different geographical populations.Additionally,B.bifidum exhibited high diversity,evident in glycoside hydrolases,the CRISPR-Cas system,and prophages.This study provides a genetic basis for further research and development of B.bifidum.

Metabolite acetyl-L-carnitine participates in Bifidobacterium animalis F1-7 to ameliorate atherosclerotic inflammation by downregulating theTLR4/NF-κB pathway

This study aimed to explore the effect of Bifidobacterium animalis F1-7 on the improvement of atherosclerotic inflammation.Arteriosclerosis model ApoE^(-/-)mice were orally administered with B.animalis F1-7 for 12 weeks.The probiotic intervention reduced the plaque areas in aorta and the accumulation of macrophages,and downregulated the expression of toll-like receptor 4(TLR4)/nuclear factorκB(NF-κB)pathway to reduce the levels of inflammatory factors.The widely-targeted metabolomics analysis showed that acetyl-L-carnitine(ALC)in the intestine of atherosclerotic mice was significantly increased after B.animalis F1-7 intervention.Correlation analysis proved that ALC was associated with atherosclerotic inflammatory response.By using oxidized low density lipoprotein induced macrophage foam cells,we further verified that ALC could reduce lipid accumulation and inflammatory response in foam cells by downregulating the TLR4/NF-κB pathway.Finally,our results revealed that B.animalis F1-7 upregulated the metabolite ALC to downregulate the inflammatory responses,leading to the reduction of plaque accumulation of atherosclerosis.

Environmental enrichment in combination with Bifidobacterium breve HNXY26M4 intervention amplifies neuroprotective benefits in a mouse model of Alzheimer's disease by modulating glutamine metabolism of the gut microbiome

The gut microbiota-brain axis has emerged as a novel target for Alzheimer's disease(AD),a neurodegenerative disease characterised by behavioural and cognitive impairment.However,most previous microbiome-based intervention studies have focused on single factors and yielded only modest cognitive improvements.Here,we proposed a multidomain intervention strategy that combined Bifidobacterium breve treatment with environmental enrichment(EE)training.In this study,we found that compared with EE or B.breve treatment alone,B.breve intervention combined with EE amplified its neuroprotective effects on AD mice,as reflected by improved cognition,inhibited neuroinflammation and enhanced synaptic function.Moreover,using microbiome and metabolome profiling,we found that the combination of B.breve and EE treatment restored AD-related gut microbiota dysbiosis and reversed microbial metabolite changes.Finally,by integrating behavioural and neurological data with metabolomic profiles,we revealed that the underlying mechanism may involve the modulation of microbiota-derived glutamine metabolism via gut-brain interactions.Collectively,combined B.breve intervention with EE treatment can alleviate AD-related cognitive impairment and improve brain function by regulating glutamine metabolism of the gut microbiome.Our findings provide a promising multidomain intervention strategy,with a combination of dietary microbiome-based and lifestyle-targeted interventions,to promote brain function and delay the progression of AD.

Preventive effects of Bifidobacterium lactis Probio-M8 on ovalbumin-induced food allergy in mice

Food allergy is a significant public health concern globally.Certain probiotics have been found to enhance food allergy by regulating immune-microbe interactions in animal models and patients.However,the effects of Bifidobacterium lactis Probio-M8 on food allergy have not been thoroughly investigated.The present study examined the anti-allergic properties of Probio-M8,particularly in relation to immune response and gut microbiota composition.Results demonstrate that oral administration of Probio-M8 effectively mitigated the allergy symptoms triggered by ovalbumin(OVA)by ameliorating the morphological damage in the jejunum,reducing OVA-specific IgE and histamine levels in the serum,and suppressing Th2 cytokines(interleukin(IL)4 and IL-13)while increasing Th1 cytokines(interferon(IFN)γ)and regulatory T(Treg)cytokines(IL-10 and transforming growth factor(TGF)β1)in the culture supernatants of splenic cells.Furthermore,Probio-M8 effectively altered the diversity and composition of gut microbiota,particularly the relative abundances of Akkermansia_muciniphila in OVA-induced mice.Compared to the OVA group,the Probio-M8 group showed a decrease in the relative abundance of Akkermansia_muciniphila.In conclusion,Probio-M8 demonstrates the potential to alleviate food allergy by regulating the Th1/Th2 response and modulating gut microbiota,thereby offering a novel therapeutic strategy for patients with food allergy.

Impact of Bifidobacterium longum NSP001 on DSS-induced colitis in conventional and humanised mice

Most scientific investigations regarding inflammatory bowel disease(IBD)pathogenesis or therapeutic strategies use dextran sulfate sodium(DSS)-induced models performed on mice.However,differences between human and animal microbiota may confound the data reproducibility from rodent experiments to clinical trials.In this study,the intervention effects of Bifidobacterium longum NSP001 on DSS-induced colitis were investigated using mice colonized with either native or humanised microbiota.Disorders in disease activity index(DAI),morphology and histology of colon tissue,intestinal permeability,and secretion of MPO,TNF-αand IL-6 were ameliorated by daily intake of live B.longum NSP001 cells in both conventional and humanised colitis mice.But the abnormal thymus index,and colonic production of ZO-1 and iNOS were improved only in colitis mice treated with B.longum NSP001 and humanised microbiome.The accumulation of acetic acid and propionic acid in colon microbiome,and the optimization of primary bile acid biosynthesis and glycerophospholipid metabolism pathways in cecum commensals were likely to explain the beneficial effects of B.longum NSP001.These data revealed that intestinal microbiome baseline would possibly affect the manifestation features of interventions by probiotics or dietary components and highlighted the necessity to include humanised microbiome while investigating potential therapeutic strategies based on rodent models.

Bifidobacterium longum CCFM1077 Attenuates Hyperlipidemia by Modulating the Gut Microbiota Composition and Fecal Metabolites:A Randomized,Double-Blind,Placebo-Controlled Clinical Trial

An increasing number of studies have indicated that gut microbiota and its metabolites are crucial in the development of hyperlipidemia.Bifidobacterium longum(B.longum)CCFM1077 has been shown to have lipid-lowering effects in animals.This study aimed to evaluate the potential of B.longum CCFM1077 in lowering the lipid levels in patients with hyperlipidemia and investigate the effect of this bacterium on serum lipid abnormalities,gut microbiota,and fecal metabolites in these patients.This study was a six-week,randomized,double-blind,and placebo-controlled pilot clinical trial.Subjects with hyperlipidemia(N=62)were randomly assigned to receive placebo(N=31)or B.longum CCFM1077(1×1010colony-forming units(CFUs)per day;N=31).Serum lipid levels including total cholesterol(TC),lowdensity lipoprotein cholesterol(LDL-C),total triglyceride(TG),and high-density lipoprotein cholesterol(HDL-C)were examined at the baseline and interventio nal endpoints.Changes in the gut microbiota composition and diversity were measured based on 16S ribosomal RNA(rRNA)sequencing of the V3-V4region at the end of the intervention period.Non-targeted metabolomics of the feces was performed using ultra-performance liquid chromatography(UPLC)-Q-Exactive Orbitrap/mass spectrometer.Oral administration of B.longum CCFM1077 for six weeks significantly decreased the serum levels of TC(p<0.01)and LDL-C(p<0.01)in patients with hyperlipidemia.B.longum CCFM1077 treatment markedly increased gut microbiota diversity and the relative abundance of anti-obesity-related genera,including Lactobacillus,Butyricicoccus,Bifidobacterium,and Blautia,whereas it decreased the relative abundance of obesity-related genera,including Alistipes,Megamonas,and Catenibacterium.Additionally,some key metabolites(bile acids(BAs),biotin,and caffeine)and their corresponding metabolic pathways(primary BA biosynthesis,and taurine and hypotaurine,biotin,purine,and caffeine metabolisms)were enriched by B.longum CCFM1077,and thus it may lower lipid levels.B.longum CCFM1077 is a probiotic strain with the potential to lower serum TC and LDL-C levels patients with hyperlipidemia.The underlying mechanism may be related to the increased abundance of anti-obesity-related genera and fecal metabolites.These findings provide a foundation for future clinical applications of lipid-lowering probiotics in managing individuals with hyperlipidemia.

Identification of Lactobacillus and Bifidobacterium 16S rRNA Gene in Breast Milk of Some Healthy Women in Kinshasa (DR Congo)

Breast milk is important for infant health. Some of its benefits are due to the presence of a specific population of bacteria in the microflora. However, the microbiome of breast milk is influenced by many parameters such as maternal diet, breastfeeding and geographic location. Culture and non-culture methods have been used in studies of this bacterial population worldwide. But in the DR Congo, there was no study reporting the use of culture-independent techniques to characterize the bacterial diversity of human milk. The aim of this study was to identify the bacterial 16S rRNA gene from two genera Lactobacillus and Bifidobacterium. The 16S rRNA gene was also identified from four species: Lactobacillus reuteri, Lactobacillus rhamnosus, Bifidobacterium longum and Bifidobacterium lactis. This analytical cross-sectional study was conducted in Kinshasa. Breast milk from some healthy women was collected from February 2 to 28, 2018. A culture-independent protocol using the classical polymerase chain reaction (PCR) was used to identify the bacterial 16S rRNA gene. The 68 samples of breast milk were collected in a sterile condition. The bacteria-specific ribosomal gene 16S rRNA was detected in 91.18% of Lactobacillus and 32.35% of Bifidobacterium at genus level. At of species level, only Lactobacillus reuteri 16S rRNA gene was identified in 89.71%. The 16S rRNA gene from the other species could not be amplified. There was also an association between educational level and the presence of Bifidobacterium and Lactobacillus 16S rRNA genes in the breast milk (p = 0.008*, p Conclusion: This study demonstrates the presence of the bacterial 16S rRNA gene from Lactobacillus and Bifidobacterium in breast milk at the genus and Lactobacillus reuteri at species level. A further study on the diet, use of antibiotics during pregnancy and lactation practice will provide a better understanding of the microflora of breast milk.

Safety Evaluations of Long-Term and Excessive Intakes of Bifidobacterium longum CLA8013: A Placebo-Controlled, Randomized, Double-Blind Study

Heat-killed Bifidobacterium longum CLA8013 has been demonstrated to improve the frequency of defecation, straining, and pain during defecation in human placebo-controlled, double-blind, parallel-group studies. We conducted a randomized, double-blind, placebo-controlled, parallel-group study to evaluate the safety of both long-term and excessive intakes of heat-killed B. longum CLA8013, when used as a food with functional claims. In both tests, 30 healthy volunteers were divided into two groups: an active group that ingested heat-killed B. longum CLA8013 and a placebo group. In the long-term intake safety study, participants in the active group ingested 25 billion cells/day for 12 weeks. In the excessive intake safety study, participants in the active group ingested 125 billion cells/day for 4 weeks. Physical, hematological, biochemical, and urine examinations were conducted, and adverse events were evaluated in both studies. The studies revealed no abnormalities in any of the safety tests. In conclusion, no safety-related issues were identified with long-term or excessive intake of heat-killed B. longum CLA8013.

Study on the Effect of Bifidobacterium Quadruple Viable Tablets in the Treatment of Ulcerative Colitis

Objective:To study the therapeutic efficacy of patients with ulcerative colitis receiving Bifidobacterium quadruple viable tablets.Methods:49 cases were selected from ulcerative colitis patients who attended the clinic from February 2021 to November 2022,and were randomly grouped into group A for addition of Bifidobacterium quadruple viable tablets treatment,and group B for conventional medication.The efficacy,inflammatory factors,nutritional indexes,and adverse reactions were compared between the groups.Results:The efficacy of UC patients in group A was higher than that in group B(P<0.05);the inflammatory factors in group A were lower than that in group B(P<0.05);nutritional indicators in group A were higher than that in group B(P<0.05);and the adverse reactions of medication in UC patients in group A were lower than that in group B(P<0.05).Conclusion:The treatment of UC patients with the addition of Bifidobacterium quadruple viable tablets can improve the nutritional status of the organism,inhibit the progression of inflammation,and is safe and efficient in treating ulcerative colitis.

Bifidobacterium pseudolongum JNFEN6低聚木糖利用效率评价及转录组学分析

探究不同双歧杆菌利用低聚木糖(xylooligosaccharide,XOS)的能力,通过细胞生理学及转录组学着重研究Bifidobacterium pseudolongum JNFEN6对XOS的高效利用机制。结果表明,XOS对不同双歧杆菌生长能力的影响不同,其对B.pseudolongum JNFEN6生长和产酸影响最为显著;以XOS为唯一碳源发酵36 h,B.pseudolongum JNFEN6菌株β-木糖苷酶活力为0.97 U/mL,发酵体系中丙酸质量浓度为85.26μg/mL;转录组学结果显示,XOS为唯一碳源培养条件下共有297个差异表达基因,其中包括136个上调基因和161个下调基因。这些基因中,ABC(ATP-binding cassette)转运渗透酶、底物结合蛋白和主要协同转运蛋白超家族(major facilitator superfamily,MFS)转运体等基因促进了XOS的转运,XOS代谢水解酶、乙酸激酶和乳酸脱氢酶等基因促进了XOS的代谢。综上所述,B.pseudolongum JNFEN6能高效利用XOS,其主要通过ABC转运系统和MFS转运系统摄取XOS,并通过“双歧分流”方式进行代谢,最终产生短链脂肪酸和其他有机化合物。本研究结果为XOS的双歧因子功能提供了理论依据。

Lactobacillus delbrueckii subsp. bulgaricus和Streptococcus thermophilus接种比例对Bifidobacterium lactis益生菌发酵乳品质的影响

将Lactobacillus delbrueckii subsp.bulgaricus ND02(LB-ND02)和Streptococcus thermophilus ND03(ST-ND03)按1∶1、1∶10、1∶100、1∶1000接种于脱脂乳中,同时接入益生菌Bifidobacterium lactis V9(B.lactis V9,接种量为2.0×107g-1),于42℃进行发酵。通过对发酵及贮藏过程中发酵乳指标的测定,评价LB-ND02和ST-ND03的接种比例对发酵乳品质的影响。结果表明,随着LB-ND02接种比例减小,凝乳时间显著延长,B.lactis V9活菌数显著提高。4℃贮藏28 d后,随LB-ND02接种比例减小,B.lactis V9存活率差异显著,后酸化也显著减弱。研究发现,LB-ND02和ST-ND03的接种比例,显著影响发酵乳的发酵时间、B.lactis V9活菌数、后酸化及黏度。

Construction of Bifidobacterium Infantis/CD Targeting Gene Therapy System

Objective： To construct Bifidobacterium Infantis/CD targeting gene therapy system. Methods： CD gene was amplified from E. Coli K12λ using PCR method, pGEX-1LamdaT plasmid and CD gene were digested with dual restriction endonucleas of EcoR Ⅰ and BamH Ⅰ and two segments of 4.9 kb and 1.3 kb were obtained. T4 DNA ligase was added to these two segments to make a recombinant CD/pGEX-1LamdaT plasmid. Then the recombinant plasmid was transfected into Bifidobacterium Infantis by electroporation. The recombinant plasmid was extracted from the positively transfected Bifidobacterium Infantis and digested with dual restriction endonucleases. Then the size of digested fragments was detected and sequencing of the gene segment inserted in extracted recombinant plasmid was performed according to the method of Sanger dideoxynucleotide triphosphate chain termination. Results： 6.2 kb recombinant plasmid was obtained from the positively transfected bacterial colony of Bifidobacterium Infantis. After being digested with dual restriction endonucleases, two segments of approximate 4.9 kb and 1.3 kb were gained from the extracted recombinant plasmid, which were equal to the size of pGEX-1LamdaT plasmid and CD gene, respectively. The full length and sequence of nucleotide acid of the inserted gene in extracted recombinant plasmid was completely identical to the CD gene. Conclusion： The foreign gene, CD gene was correctly inserted into pGEX-1LambdaT plasmid and transferred into Bifidobacterium Infantis. Bifidobacterium Infantis/CD targeting gene therapy system was successfully constructed.

益生菌Lactobacillus casei Zhang和Bifidobacterium lactis V9接种比例及乳固形物含量对其活菌数的影响

将益生菌Lactobacillus casei Zhang和Bifidobacterium lactis V9按1∶3、1∶1、3∶1(总接种量为2×106cfu/g)接种于总固形物含量为10%、12%、14%、16%的脱脂牛乳中,37℃恒温发酵至pH 4.5,于4℃贮藏28 d。测定发酵及贮藏结束2株益生菌活菌数。试验结果表明,发酵结束,当研究固形物质量分数相同,接种比例为3∶1时,L.casei Zhang和B.lactis V9的活菌数最高。贮藏结束,当接种比例相同,所含乳固形物质量分数为14%时,两株益生菌存活率显著高于其他固形物含量组(P<0.05)。本研究显示,L.casei Zhang和B.lactis接种比例为3∶1,乳固形物质量分数为14%时,两株益生菌生长良好且存活率高,适宜生产应用。

Bifidobacterium lactis V9在脱脂乳粉中贮藏稳定性的研究

研究Bifidobacterium lactis V9(B.lactis V9)与双歧杆菌B在脱脂乳粉中不同温度条件下存活稳定性,并以Arrhenius方程反映温度与菌体损失率之间关系,预测B.lactis V9与双歧杆菌B相关乳粉产品货架期内菌体损失情况。结果表明,B.lactis V9与双歧杆菌B随温度升高,菌体损失率增大。两菌株在37℃贮藏28 d后,活菌数下降最明显,约两个数量级,且在不同贮藏温度下活菌数随时间变化情况无显著性差异。通过Arrhenius方程和菌体递减模型,建立了B.lactis V9和双歧杆菌B在不同温度下货架期预测模型,该模型可以较好的预测含B.lactis V9和双歧杆菌B乳粉产品在某一温度下菌体损失率和货架期寿命。

Lactobacillus casei Zhang和Bifidobacterium lactis V9在益生菌酸乳中的应用

益生菌在酸乳中的应用已非常普遍,将Lactobacillus casei Zhang单独(样品A)以及与Bifidobacterium lactis V9复合(样品B),同酸乳发酵剂(G027)共同发酵益生菌酸乳,于4℃贮藏21 d。结果表明,整个贮藏期间2组样品间的黏度和持水性差异不显著;贮藏期间2组样品间L.casei Zhang的活菌数没有差异,且L.casei Zhang和B.lactis V9的活菌数不随贮藏时间而降低;L.casei Zhang和B.lactis V9复合益生菌酸奶感官评价优于单独添加L.casei Zhang酸乳。L.casei Zhang和B.lactis V9复合添加,更适合于益生菌酸乳的生产。

响应曲面法优化短双歧杆菌Bifidobacterium breve A04培养基

本文通过响应曲面法(RSM)达到优化双歧杆菌培养基组分的目的。以TPYG培养基为基础培养基,采用FFD(factionalfactorialdesign)实验设计法,筛选出三种最佳生长强化因子葡萄糖、酵母粉和初始pH值;通过快速登高法摸索出生长强化因子的最佳浓度范围为:葡萄糖5.0g/L,酵母膏3.01g/L以及初始pH6.0;利用旋转中心组分设计法(RCD)和响应曲面法(RSM)确定关键组分的最佳浓度并进行了验证。最终优化培养基组分为葡萄糖5.194g/L,酵母膏2.829g/L,低聚果糖2g/L,西红柿汁50ml,肝浸液5g/L,Tween801ml,半胱氨酸盐酸盐0.3g/L,pH6.463。最终优化出的培养基获得的菌体干重达到4.462g/L,比优化前3.16g/L提高了1.43倍。

Influence of whole peptidoglycan of bifidobacterium on cytotoxic effectors produced by mouse peritoneal macrophages

INTRODUCTIONBifidobacteria are physiologically beneficial bacteria which are perdominant in human intestine ,and possess the most important functions .They play an important role in maintaining microbial balance of the intestine .Furthermore , their presence is thought to be an important indication of health of the body [1-4].Whole peptidoglycan ( WPG) is the major component in the cell wall of bifidobacterium ,which is also a biological responsemodifier with nontoxic side dffcets.

Anti-inflammatory activity of probiotic Bifidobacterium: Enhancement of IL-10 production in peripheral blood mononuclear cells from ulcerative colitis patients and inhibition of IL-8 secretion in HT-29 cells

AIM: To determine the anti-inflammatory activity of probiotic Bifidobacteria in Bifidobacteria-fermented milk (BFM) which is effective against active ulcerative colitis (UC) and exacerbations of UC, and to explore the immunoregulatory mechanisms. METHODS: Peripheral blood mononuclear cells (PBMNC) from UC patients or HT-29 cells were co-cultured with heat-killed probiotic bacteria or culture supernatant of Bifidobacterium breve strain Yakult (BbrY) or Bifidobacterium bifidum strain Yakult (BbiY) to estimate the amount of IL-10 or IL-8 secreted. RESULTS: Both strains of probiotic Bifidobacteria contained in the BFM induced IL-10 production in PBMNC from UC patients, though BbrY was more effective than BbiY. Conditioned medium (CM) and DNA of both strains inhibited IL-8 secretion in HT-29 cells stimulated with TNF-α, whereas no such effect was observed with heat- killed bacteria. The inhibitory effect of CM derived from BbiY was greater than that of CM derived from BbrY. DNAs of the two strains had a comparable inhibitory activity against the secretion of IL-8. CM of BbiY induced a repression of IL-8 gene expression with a higher expression of IκB-ζ mRNA 4 h after culture of HT-29 cells compared to that in the absence of CM.CONCLUSION: Probiotic Bifidobacterium strains in BFM enhance IL-10 production in PBMNC and inhibit IL-8 secretion in intestinal epithelial cells, suggesting that BFM has anti-inflammatory effects against ulcerative colitis.

Effect of Lactobacillus rhamnosus HN001 and Bifidobacterium longum BB536 on the healthy gut microbiota composition at phyla and species level: A preliminary study

AIMTo evaluate the ability of Lactobacillus rhamnosus HN001 and Bifidobacterium longum BB536 to colonize the intestinal environment of healthy subjects and modify the gut microbiota composition.METHODSTwenty healthy Italian volunteers, eight males and twelve females, participated in the study. Ten subjects took a sachet containing 4 × 109 colony-forming units (CFU) of Bifidobacterium longum BB536 and 109 CFU of Lactobacillus rhamnosus HN001, 30 min before breakfast (pre-prandial administration), while ten subjects took a sachet of probiotic product 30 min after breakfast (post-prandial administration). The ability of Lactobacillus rhamnosus HN001 and Bifidobacterium longum BB536 to colonize human gut microbiota was assessed by means of quantitative real-time PCR, while changes in gut microbiota composition were detected by using Ion Torrent Personal Genome Machine.RESULTSImmediately after 1-mo of probiotic administration, B. longum BB536 and L. rhamnosus HN001 load was increased in the majority of subjects in both pre-prandial and post-prandial groups. This increase was found also 1 mo after the end of probiotic oral intake in both groups, if compared to samples collected before probiotic consumption. At phyla level a significant decrease in Firmicutes abundance was detected immediately after 1-mo of B. longum BB536 and L. rhamnosus HN001 oral intake. This reduction persisted up to 1 mo after the end of probiotic oral intake together with a significant decrease of Proteobacteria abundance if compared to samples collected before probiotic administration. Whereas, at species level, a higher abundance of Blautia producta, Blautia wexlerae and Haemophilus ducrey was observed, together with a reduction of Holdemania filiformis, Escherichia vulneris, Gemmiger formicilis and Streptococcus sinensis abundance. In addition, during follow-up period we observed a further reduction in Escherichia vulneris and Gemmiger formicilis, together with a decrease in Roseburia faecis and Ruminococcus gnavus abundance. Conversely, the abundance of Akkermansia muciniphila was increased if compared to samples collected at the beginning of the experimental time courseCONCLUSIONB. longum BB536 and L. rhamnosus HN001 showed the ability to modulate the gut microbiota composition, leading to a significant reduction of potentially harmful bacteria and an increase of beneficial ones. Further studies are needed to better understand the specific mechanisms involved in gut microbiota modulation.

Protective effect of Bifidobacterium infantis CGMCC313-2 on ovalbumin-induced airway asthma and b-lactoglobulininduced intestinal food allergy mouse models

AIM To determine whether oral administration of Bifidobacterium infantis CGMCC313-2(B. infantis CGMCC313-2) inhibits allergen-induced airway inflammation and food allergies in a mouse model.METHODS Ovalbumin(OVA)-induced allergic asthma and b-lactoglobulin-induced food allergy mouse models were used in this study. Following oral administration of B. infantis CGMCC313-2 during or after allergen sensitization, histopathologic changes in the lung and intestine were evaluated by hematoxylin and eosin(HE) staining. In the allergic asthma mouse model, we evaluated the proportion of lung-infiltrating inflammatory cells. OVAspecific IgE and IgG1 levels in serum and cytokine levels in bronchoalveolar lavage fluid(BALF) were also assessed. In the food allergy mouse model, the levels of total Ig E and cytokines in serum were measured.RESULTS Oral administration of B. infantis CGMCC313-2 during or after allergen sensitization suppressed allergic inflammation in lung and intestinal tissues, while the proportion of infiltrating inflammatory cells was significantly decreased in the BALF of allergic asthma mice. Moreover, B. infantis CGMCC313-2 decreased the serum levels of total Ig E in food allergy mice, and reductions in IgE and IgG1 were also observed in OVA-induced allergic asthma mice. The expression of interleukin-4(IL-4) and IL-13 in both serum and BALF was suppressed following the administration of B. infantis CGMCC313-2, while an effect on serum IL-10 levels was not observed.CONCLUSION B. infantis CGMCC313-2 inhibits the secretion of allergen-induced IgE, IL-4 and IL-13, and attenuates allergic inflammation.