Backgrounds: Maternal food additive intake was found to induce gut dysbiosis in offsprings and increased risk to colitis in animal models. We aimed to assess the impact of maternal food additive intake on early life gut bacteriome, mycobiome and virome development and vertical bacteria strain transmission between women with inflammatory bowel disease (IBD) and their infants.

Methods: A total of 553 fecal samples from 145 mothers (25 with IBD) and 280 faecal samples from 145 infants (25 born to IBD mothers) from three regions/cities in China (Hong Kong, Foshan, Kunming) were subjected to shotgun metagenomic sequencing. Recent food additives (FA, last 12 months) intake was collected during pregnancy using a validated questionnaire and defined based on high (Q4) or normal (Q1-3) interquartile range. Subjects were assigned to four groups according to their disease status and FA consumption, namely: non-IBD-normal FA (N = 94), non-IBD-high FA (N = 26), IBD-normal FA (N = 8), and IBD-high FA (N = 9). Clinical data including delivery mode, antibiotic use, smoking habits and breastfeeding were collected. We analysed gut microbiome and virome diversity and composition of stool as well as vertical gut bacterial strain sharing/transmission between mother and infants.

Results: IBD mothers were more likely to have higher FA, particularly emulsifiers, consumption (Odds ratio: 3.87) than non-IBD mothers. IBD mothers with high FA intake exhibited lower gut bacteria and virome diversity and richness during pregnancy compared with non-IBD mothers (Fig 1A and Fig 1B). Pairwise analysis with multiple dimension scale (MDS) showed significant differences in gut microbiome composition amongst groups. Permutational multivariate analysis of variance showed that current FA intake contributed most to the microbiome beta-diversity, followed by having IBD and age (Fig 1C).

Among the 216 bacterial species that were found to be present in non-IBD mothers with normal food additive intake, we found two bacteria taxa, Faecalibacterium prausnitzii and Streptococcus parasanguinis, were altered in the offspring microbiome. FA intake was associated with increased vertical sharing of Streptococcus parasanguinis and decreased sharing of Faecalibacterium prausnitzii in IBD mothers and their infants. The impact of FA intake in IBD mothers on postnatal microbiome in infants lasted up to six months.

Conclusions: This is the first human study to report the impact of maternal food additive intake on postnatal microbiome and bacteria sharing in IBD mothers and their infants. Further research to unravel underlying mechanisms and implications on risk of IBD in the infants are warranted.

Acknowledgment: This study was funded by InnoHK, The Government of Hong Kong, the Special Administrative Region of the People’s Republic of China and The Leona M. and Harry B. Helmsley Charitable Trust.

Ling Lin

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