Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo, 657-8501, Japan.
Energy Technology Laboratories, OSAKA GAS CO., LTD., 6-19-9 Torishima, Konohana-ku, Osaka, 554-0051, Japan.
Sci Rep. 2020 May 22;10(1):8516. doi: 10.1038/s41598-020-65561-5.
The ketone body D-β-hydroxybutyrate (DBHB) has gained attention owing to its cellular signalling function; however, its effect on the human colonic microbiota remains unclear. Here, DBHB dynamics in the human colon were investigated using an in vitro colonic microbiota model, which maintained most of the operational taxonomic units detected in the original faeces. Over 54% of 0.41% (w/v) DBHB was metabolised by microbiota models originating from seven faecal samples after 30 h of fermentation (regarded as DBHB utilisers); however, <19% of DBHB was metabolised by microbiota models from five faecal samples (regarded as non-utilisers of DBHB). In utilisers, DBHB administration increased the relative abundance of the genus Coprococcus, correlated with increased butyrogenesis. Increased butyrogenesis was not observed in DBHB non-utilisers. Based on PICRUSt analysis, the relative abundance of β-hydroxybutyrate dehydrogenase was maintained in microbiota models from DBHB utilisers following DBHB administration; however, it decreased in microbiota models from non-utilisers. After 21 h of fermentation, the intracellular glutamate concentration, which is indicative of growth, showed a positive correlation with DBHB utilisation (R = 0.70). Human colonic microbiotas with high growth activity demonstrate efficient utilisation of DBHB for increased butyrate production, which affords health benefits.
酮体 D-β-羟基丁酸 (DBHB) 因其细胞信号功能而受到关注;然而，其对人类结肠微生物群的影响尚不清楚。在这里，使用体外结肠微生物群模型研究了 DBHB 在人类结肠中的动态，该模型保留了在原始粪便中检测到的大多数操作分类单位。在 30 小时的发酵后，来自七个粪便样本的微生物群模型代谢了 0.41%(w/v)的超过 54%的 DBHB(被认为是 DBHB 的利用者);然而，来自五个粪便样本的微生物群模型仅代谢了不到 19%的 DBHB(被认为是非 DBHB 的利用者)。在利用者中，DBHB 的给药增加了粪球菌属的相对丰度，与丁酸生成的增加相关。在 DBHB 非利用者中未观察到丁酸生成增加。基于 PICRUSt 分析，在 DBHB 给药后，来自 DBHB 利用者的微生物群模型中β-羟丁酸脱氢酶的相对丰度得以维持;然而，在非利用者的微生物群模型中，其相对丰度下降。在发酵 21 小时后，指示生长的细胞内谷氨酸浓度与 DBHB 的利用呈正相关(R=0.70)。具有高生长活性的人类结肠微生物群表现出对 DBHB 的有效利用，以增加丁酸的产生，从而带来健康益处。
