Exposure to environmental microbiota explains persistent abdominal pain and irritable bowel syndrome after a major flood

Abstract

Background: After an environmental disaster, the affected community is at increased risk for persistent abdominal pain but mechanisms are unclear. Therefore, our study aimed to determine association between abdominal pain and poor water, sanitation and hygiene (WaSH) practices, and if small intestinal bacterial overgrowth (SIBO) and/or gut dysbiosis explain IBS, impaired quality of life (QOL), anxiety and/or depression after a major flood.

Results: New onset abdominal pain, IBS based on the Rome III criteria, WaSH practices, QOL, anxiety and/or depression, SIBO (hydrogen breath testing) and stools for metagenomic sequencing were assessed in flood victims. Of 211 participants, 37.9% (n = 80) had abdominal pain and 17% (n = 36) with IBS subtyped diarrhea and/or mixed type (n = 27 or 12.8%) being the most common. Poor WaSH practices and impaired quality of life during flood were significantly associated with IBS. Using linear discriminant analysis effect size method, gut dysbiosis was observed in those with anxiety (Bacteroidetes and Proteobacteria, effect size 4.8), abdominal pain (Fusobacteria, Staphylococcus, Megamonas and Plesiomonas, effect size 4.0) and IBS (Plesiomonas and Trabulsiella, effect size 3.0).

Conclusion: Disturbed gut microbiota because of environmentally-derived organisms may explain persistent abdominal pain and IBS after a major environmental disaster in the presence of poor WaSH practices.

Keywords: Abdominal pain; Dysbiosis; Flood; Malaysia; Sanitation and hygiene practices; Small intestinal bacterial overgrowth; Water.

Fig. 1

A map of Peninsular Malaysia showing the Kelantan river that caused the major flood, and location of the two villages that were involved in our study

Fig. 2

Flow chart of study recruitment

Fig. 3

Principal component analysis (PCoA) based on Jensen-Shannon divergence identifies two clusters based on anxiety scores (a), and the score is higher in cluster 1 than 2. Not shown here is the Shannon Index which is significantly lower in cluster 1 than 2 (4.8 vs. 5.5, P < 0.001). Taxonomic representation of microbial composition of both clusters is shown in (b), with cluster 1 in red and cluster 2 in green. Histogram of the LDA effect size for both clusters is shown in (c). The most differentially abundant bacterial taxa observed in cluster 1 are the phyla Bacteroidetes (including the genus Prevotella) and Proteobacteria with effect size of 4.8

Fig. 4

Taxonomic representation and histogram of the LDA effect size for microbial composition in those with persistent abdominal pain (a and b) and IBS (c and d) are shown here. For those victims with abdominal pain (a and b), Fusobacteria is the most abundant with effect size of 4.0. Others of significance include the Staphylococcus, Megamonas and Plesiomonas. For those with IBS (c and d), Plesiomonas and Trabulsiella are the most abundant with effect size approaching 3.0