A recent study highlights the importance of specific gut bacteria strains in processing dietary fiber, which doctors recommend for healthy digestion. Research indicates that not just the presence of certain gut bacteria, but also the right strains are essential for effectively processing resistant starches, suggesting a move towards precision nutrition.
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Dietary fiber, found in legumes, nuts, seeds, vegetables, fruits, and whole grains, helps prevent constipation, supports beneficial gut microbes, and regulates blood sugar. However, previous studies on the effects of resistant starches yielded mixed results, with some individuals benefiting while others did not. Angela Poole, assistant professor in Nutritional Sciences, noted that the variation may stem from the necessity of having the appropriate gut bacteria to process resistant starch.
The study, published on July 24 in Microbiology Spectrum, utilized advanced techniques to identify different strains of Bifidobacterium adolescentis, a gut microbe with unique responses to resistant starches. Poole emphasized the need for a granular approach to studying gut bacteria, stating, "We need better tools to get more comprehensive characterizations of what the bacteria are and what they’re doing."
While previous research typically employed 16S sequencing to identify bacterial presence, this study utilized shotgun metagenomics, which allows for strain-level identification and gene analysis. This methodology enables researchers to determine the genetic functions of bacterial strains.
The research involved more than 50 participants who consumed three types of crackers—two containing resistant starches (types 2 and 4) and one control starch processed by the body without bacterial enzymes. The investigation also employed a sensitive bioinformatics tool, Cayman, to uncover additional genes in bacteria that break down resistant starch.
The findings suggested the existence of previously uncharacterized bacteria that increase in number in the presence of resistant starch, indicating their role in carbohydrate processing. Future research aims to delve deeper into these bacteria.
Poole remarked on the implications for personalized nutrition, particularly in diabetes management; knowing which strain of Bifidobacterium adolescentis a patient has could inform dietary recommendations. The study, funded by Cornell University and the European Union, included contributions from Nicola Segata and Francesco Asnicar from the University of Trento, Italy.