Lifestyle related changes with partially hydrolyzed guar gum dietary fiber in healthy athlete individuals – A randomized, double-blind, crossover, placebo-controlled gut microbiome clinical study

The gut microbiomes association towards a favorable health profile is a rapidly emerging active area of research. This randomized, double-blind, crossover, placebo-controlled study elucidates the impact of prebiotic partially hydrolyzed guar gum (PHGG) dietary fiber on the relative abundance of the gut microbiomes (16S rRNA gene sequencing) and their significant correlation with fecal defecation characteristics among healthy male athletes. Subjects followed a daily six grams dietary intake of either PHGG or placebo for four weeks, following a three weeks washout period, subjects followed another four weeks of crossover alternative administration. Fecal defecation characteristics were assessed using a questionnaire along with quality of life (QOL) questions. The results demonstrated that genus level alteration in gastrointestinal microbiomes relative abundance was correlated to representative changes in fecal defecation characteristics, especially in reduction of diarrhea (P = 0.035) and fecal excretory feeling (P = 0.038). The PHGG intake led to a significant increase in phylum Actinobacterium (P = 0.04), along with a significant decrease in Bacteroidetes (P = 0.036). Also, a trending decrease in Firmicutes (P = 0.09) was noticed. At genus level, a significant alteration in the relative abundance of Bifidobacterium (P = 0.047) and Clostridium subcluster XI (P = 0.044) were observed with PHGG intake compared with placebo. Reduction in diarrhea was associated with the relative abundance of phylum Firmicutes/Bacteroidetes ratio and genera Bacteroides/Prevotella ratio for the PHGG intervention compared to placebo. In summary, the finding reveals that even at relatively low dosage, intake of prebiotic PHGG dietary fiber modulates gastrointestinal microbiomes, and thus improves gut health.