Gut bacteria selectively promoted by dietary fibers alleviate type 2 diabetes.
Zhao L, Zhang F, Ding X, Wu G, Lam YY, Wang X, Fu H, Xue X, Lu C, Ma J, Yu L, Xu C, Ren Z, Xu Y, Xu S, Shen H, Zhu X, Shi Y, Shen Q, Dong W, Liu R, Ling Y, Zeng Y, Wang X, Zhang Q, Wang J, Wang L, Wu Y, Zeng B, Wei H, Zhang M, Peng Y, Zhang C
Science. Mar 2018. doi: 10.1126/science.aao5774
COMMENT: This publication in Science is centered around the benefits that the short-chain fatty acid (SCFA), produced by some gut commensal bacteria, exercise over Type 2 Diabetes Mellitus (T2DM) patients. In a randomized clinical study the authors are able to detect a group of SCFA-producing strains, promoted by diets rich in vegetal fiber, that appears to improve hemoglobin A1c levels in the T2DM patients. This group of SCFA-producing strains also appears to diminish indole and hydrogen sulfide production, which is metabolically detrimental. This study provides a new possible via for intervention in T2DM since restoration of these SCFA-producing strains appears to improve health parameters in T2DM patients.
In the study there were 2 groups of T2DM patients, the W group with significantly higher intake of dietary fiber than the U group, but the daily energy and macronutrient intakes were similar across groups. The authors got to transfer to mice the effects of the treatments by microbial transplantation:
We transplanted the pre- and postintervention gut microbiota from the same participants into germ-free C57BL/6J mice. The mice that received pre- or postintervention microbiota showed more similarity in gut microbiota to their donors than to each other (fig. S2). Mice transplanted with the postintervention microbiota from either the W or U group showed better metabolic health parameters than those with the preintervention microbiota from the corresponding group. Mice that received postintervention microbiota from the W group had the lowest fasting and postprandial blood glucose levels among all gnotobiotic mice.
Acetic acid in W and U groups were significantly enriched after intervention and butyric acid production was increased only in W group. These changes appeared to be produced by a group of acetate and butyrate-producing bacterial strains that were selectively promoted by increased availability of diverse fermentable carbohydrates from vegetal fibers. The authors propose that these findings can open new ways for T2DM prevention and treatment:
... promoting this active group of SCFA producers not only enhanced a beneficial function but also maintained a gut environment that keeps detrimental bacteria at bay. Targeted promotion of the active SCFA producers as ecosystem service providers via personalized nutrition may present a novel ecological approach for manipulating the gut microbiota to manage T2DM and potentially other dysbiosis-related diseases.