Effects of cereal fiber on bowel function: A systematic review of intervention trials

AIM: To comprehensively review and quantitatively summarize results from intervention studies that examined the effects of intact cereal dietary fiber on parameters of bowel function. METHODS: A systematic literature search was conducted using Pub Med and EMBASE. Supplementary literature searches included screening reference lists from relevant studies and reviews. Eligible outcomes were stool wet and dry weight, percentage water in stools, stool frequency and consistency, and total transit time. Weighted regression analyses generated mean change(± SD) in these measures per g/d of dietary fiber. RESULTS: Sixty-five intervention studies among generally healthy populations were identified. A quantitative examination of the effects of non-wheat sources of intact cereal dietary fibers was not possible due to an insufficient number of studies. Weighted regression analyses demonstrated that each extra g/d of wheat fiber increased total stool weight by 3.7 ± 0.09 g/d(P < 0.0001; 95%CI: 3.50-3.84), dry stool weight by 0.75 ± 0.03 g/d(P < 0.0001; 95%CI: 0.69-0.82), and stool frequency by 0.004 ± 0.002 times/d(P = 0.0346; 95%CI: 0.0003-0.0078). Transittime decreased by 0.78 ± 0.13 h per additional g/d(P < 0.0001; 95%CI: 0.53-1.04) of wheat fiber among those with an initial transit time greater than 48 h.CONCLUSION: Wheat dietary fiber, and predominately wheat bran dietary fiber, improves measures of bowel function.

Recurrent evolution of seaweed body plan complexity among photosynthetic eukaryotes

The evolutionary origin of multicellularity is an age-old question in biological research.Diverse studies have delved into the evolutionary processes that led to the evolution of multicellular life forms from unicellular ancestors.The beauty and the challenge about this topic are that evolution has brought forth various forms of multicellular life,multiple times independently,scattered across the evolutionary tree of eukaryotes.Adding to the challenge,multicellular organisms exist in a diversity of forms and complexities,and the mechanisms by which multicellularity emerged are also likely different between animals,algae,or fungi(Niklas and Newman,2020).Recently,Nelson et al.(2024)presented a large-scale comparative genomics study focused on particularly intricate multicellular organisms:macroalgae(seaweeds),which emerged independently in three distinct eukaryotic lineages-green algae(Chlorophyta),red algae(Rhodophyta),and brown algae(Phaeophyceae).

Punctuated ancestral gene gains in streptophyte evolution

Understanding the genomic substrate behind evolutionary change is a major endeavor in biology,shedding light on impor-tant aspects of the evolutionary history as well as unraveling the mechanisms of genome evolution.One of the foremost drivers of genomic evolution at a macroevolutionary scale is the origin of new genes.