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.

肠道微生物群与健康状况的良好联系是一个迅速兴起的活跃研究领域。这项随机，双盲，交叉，安慰剂对照的研究阐明了益生元部分水解的瓜尔豆胶（PHGG）膳食纤维对肠道菌群相对丰度的影响（16S rRNA基因测序）以及它们与粪便排便特征之间的显着相关性健康的男运动员。在三周的清除期之后，受试者每天接受六克PHGG或安慰剂的饮食摄入，持续四个星期，受试者随后又进行了四周的交叉替代给药。使用问卷和生活质量（QOL）问题评估粪便排泄特征。结果表明，胃肠菌群相对丰度的属水平变化与粪便排泄特征的代表性变化有关，特别是在减少腹泻（P = 0.035）和粪便排泄感（P = 0.038）方面。PHGG摄入量导致门脉显着增加放线菌（P = 0.04），以及拟杆菌的显着减少（P = 0.036）。此外，还注意到硬毛的下降趋势（P = 0.09）。在属水平上，与安慰剂相比，PHGG摄入量观察到双歧杆菌（C = 0.047）和梭状芽胞杆菌XI的相对丰度有显着变化（P = 0.044）。腹泻的减少与硬毛门/拟杆菌门的相对丰度和拟杆菌/普雷沃氏菌的种类有关PHGG干预与安慰剂的比例。总而言之，该发现表明，即使以相对较低的剂量摄入益生元PHGG膳食纤维也可以调节胃肠道微生物群，从而改善肠道健康。