Intestinal Faecalibacterium Prausnitzii Abundance Correlates With The Effect Of High-Dose Thiamine On Chronic Fatigue In Patients With IBD In Remission

Gut microbiome analysis in previous studies has shown that IBD patients with fatigue symptoms were characterized by a significant reduction in butyrate-producing bacteria in the colon and a less diverse microbiome. Although some gut bacteria can produce thiamine in the gut environment, many butyrate-producing bacteria, including Faecalibacterium prausnitzii, appear to depend on dietary thiamine or cross-feeding from other bacterial species in the colon. In some situations, a lack of thiamine in the colon may thus reduce the number of butyrate-producing bacteria, and thereby butyrate levels in the colon. Recently, a randomized, double-blinded, placebo-controlled crossover trial revealed that high-dose oral thiamine significantly reduced chronic fatigue in IBD patients in remission. Here, we analyzed the microbiota and short-chain fatty acids concentrations in fecal samples from that study to test the possibility that the beneficial effect of thiamine on chronic fatigue was explained by induced changes in the microbiome, including increased levels of butyrate-producing bacteria and butyrate. However, we found no differences in butyrate nor butyrate-producing bacteria between controls and chronic fatigue patients or during the treatment by comparing placebo vs. treated patients. Interestingly, a negative correlation between F. prausnitzii relative abundance in fecal samples and IBD fatigue score change was seen in thiamine-treated
patients with chronic fatigue.