The Composition and Diversity of the Gut Microbiota in Children Is Modifiable by the Household Dogs: Impact of a Canine-Specific Probiotic.

Carlos Gómez-Gallego,Maria Carmen Collado,Mira Forsgren,Merja Nermes,Seppo Salminen,Marta Selma-Royo,Erika Isolauri,Shea Beasley

doi:10.3390/microorganisms9030557

Abstract

The development of the infant gut microbiota is initiated during pregnancy and continued through early life and childhood, guided by the immediate environment of the child. Our aim was to characterize the shared microbiota between dogs and children as well as to determine whether introduction to dogs of a dog-specific probiotic combination modifies the transfer process. We studied 31 children from allergic families with pet dog(s) and 18 control families without a dog. Altogether 37 dogs were randomized for a 4-week period in a double-blind design to receive canine-derived probiotic product containing a mixture of L. fermentum, L. plantarum, and L. rhamnosus, or placebo. Fecal samples from children and dogs were taken before and after the treatment. Distinctive gut microbiota composition was observed in children with dogs compared to those without a dog, characterized by higher abundance of Bacteroides and short-chain fatty acid producing bacteria such as Ruminococcus and Lachnospiraceae. Probiotic intervention in dogs had an impact on the composition of the gut microbiota in both dogs and children, characterized by a reduction in Bacteroides. We provide evidence for a direct effect of home environment and household pets on children microbiota and document that modification of dog microbiota by specific probiotics is reflected in children’s microbiota.

Highlights

Humans and microbes create a symbiotic coexistence comprising bidirectional exchange of endocrine, immune and neural signals with targets in metabolic, immune, humoral and neural pathways [1]
The objective of the present study was to expand our understanding of the impact of household dog exposure on children’s microbiota in an urban environment: first, by comparing the gut microbiota composition in children from allergic families with and without dogs; and second, by determining whether the changes induced in dog microbiota by probiotics are reflected in children microbiota composition
Children fecal microbiota was dominated for microorganisms belonging to the families Lachnospiraceae, Bifidobacteriaceae, Bacteroidaceae, Streptococcaceae and Ruminococcaceae, while dog fecal microbiota is dominated for the families Lachnospiraceae, Peptostreptococcaceae and Erysipelotrichaceae

Summary

Introduction

Humans and microbes create a symbiotic coexistence comprising bidirectional exchange of endocrine, immune and neural signals with targets in metabolic, immune, humoral and neural pathways [1]. Recent advances in elucidating early host–microbe interactions suggest that a shift in the gut microbiota composition, i.e., dysbiosis, comprises a prerequisite in the development of non-communicable diseases [2]. Aberrancies in the microbiota composition and activity may be transferred to the infant by different routes: from the mother during pregnancy, at delivery via microbes in the mother’s birth canal and during breastfeeding from human milk or through a close contact with the proximate environment. The former has attracted scientific interest, while the environmental exposures remain less well characterized. The former has attracted scientific interest, while the environmental exposures remain less well characterized. 4.0/).

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