4. Discussion
diarrhea-associated bowel
We tested the prebiotic properties of resistant potato starch (RPS) by administering 3.5 g or 7 g of RPS per day for 4 weeks and measuring the relative abundance of Bifidobacterium and scores of bowel movement consistency. Participants in the 3.5 g RPS arm demonstrated significantly higher increases in the relative abundance of Bifidobacterium compared to the placebo arm, along with fewer Type 7 (liquid consistency with no solid pieces) and Type 1 or 2 (separate hard lumps and/or lumpy and sausage-like) bowel movements compared to the placebo groups, thereby meeting prebiotic criteria [Participants in the 7 g RPS arm had responses similar to those in the 3.5 g arm, but only improvements in diarrhea-associated bowel movement scores met statistical significance. Interestingly, while the relative abundance of The genus This novel study is the first to demonstrate increases in health-associated bacteria There are limitations to this study, including the short duration. Bowel movement records were not kept beyond the 4-week timepoint, making it difficult to connect changes in bowel movement scores to changes in the composition of the gut microbiota derived from a stool sample collected at the end of the study. We compensated for this limitation by analyzing the final seven bowel movements recorded for each participant, which we reasoned was an appropriate approximation of the bowel movements consistent with the microbiota composition at 4 weeks. A longer study would also be useful to confirm the stability of these findings. It is possible that baseline levels of bacteria and stool consistency reflect cessation of vitamin and/or dietary supplement consumption, and future studies would benefit from recruiting participants earlier for a longer ‘wash-out’ period. The short duration also limited the investigation into the effects of RPS on the gut microbiota, which has pronounced beneficial effects at higher doses for longer durations [