Individuals in a community who developed irritable bowel syndrome (IBS) after major floods have significant mental health impairment. We aimed to determine if Bifidobacterium infantis M-63 was effective in improving symptoms, psychology and quality of life measures in flood-affected individuals with IBS and if the improvement was mediated by gut microbiota changes. Design was non-randomised, open-label, controlled before-and-after. Of 53 participants, 20 with IBS were given B. infantis M-63 (1×109 cfu/sachet/day) for three months and 33 were controls. IBS symptom severity scale, hospital anxiety and depression scale, SF-36 Questionnaire, hydrogen breath testing for small intestinal bacterial overgrowth and stools for 16S rRNA metagenomic analysis were performed before and after intervention. 11 of 20 who were given probiotics (M-63) and 20 of 33 controls completed study as per-protocol. Mental well-being was improved with M-63 vs controls for full analysis (P=0.03) and per-protocol (P=0.01) populations. Within-group differences were observed for anxiety and bodily pain (both P=0.04) in the M-63 per-protocol population. Lower ratio of Firmicutes/Bacteroidetes was observed with M-63 vs controls (P=0.01) and the lower ratio was correlated with higher post-intervention mental score (P=0.04). B. infantis M-63 is probably effective in improving mental health of victims who developed IBS after floods and this is maybe due to restoration of microbial balance and the gut-brain axis. However, our conclusion must be interpreted within the context of limited sample size. The study was retrospectively registered on 12 October 2017 and the Trial Registration Number (TRN) was NCT03318614.
This 10-months randomised, double-blind, parallel and placebo-controlled study evaluated the effects of Bifidobacterium longum BB536 on diarrhoea and/or upper respiratory illnesses in 520 healthy Malaysian pre-school children aged 2-6 years old. The subjects randomly received a one-gram sachet containing either BB536 (5×109 cfu) or placebo daily. Data analysis was performed on 219 subjects who fully complied over 10-months (placebo n=110, BB536 n=109). While BB536 did not exert significant effects against diarrhoea in children, Poisson regression with generalised estimating equations model indicated significant intergroup difference in the mean number of times of respiratory illnesses over 10 months. The duration of sore throat was reduced by 46% (P=0.018), with marginal reduction for duration of fever (reduced by 27%, P=0.084), runny nose (reduced by 15%, P=0.087) and cough (reduced by 16%, P=0.087) as compared to the placebo. Principal coordinate analysis at genus level of the gut microbiota revealed significant differences between 0 and 10 months in the BB536 group (P<0.01) but not in placebo group (P>0.05). The abundance of the genus Faecalibacterium which is associated with anti-inflammatory and immuno-modulatory properties was significantly higher in the BB536 group (P<0.05) compared to the placebo group. Altogether, our present study illustrated the potential protective effects of BB536 against upper respiratory illnesses in pre-school Malaysian children, with gut microbiota modulating properties.