Exposure to household furry pets influences the gut microbiota of infants at 3–4 months following various birth scenarios

Abstract

BackgroundEarly-life exposure to household pets has the capacity to reduce risk for overweight and allergic disease, especially following caesarean delivery. Since there is some evidence that pets also alter the gut microbial composition of infants, changes to the gut microbiome are putative pathways by which pet exposure can reduce these risks to health. To investigate the impact of pre- and postnatal pet exposure on infant gut microbiota following various birth scenarios, this study employed a large subsample of 746 infants from the Canadian Healthy Infant Longitudinal Development Study (CHILD) cohort, whose mothers were enrolled during pregnancy between 2009 and 2012. Participating mothers were asked to report on household pet ownership at recruitment during the second or third trimester and 3 months postpartum. Infant gut microbiota were profiled with 16S rRNA sequencing from faecal samples collected at the mean age of 3.3 months. Two categories of pet exposure (i) only during pregnancy and (ii) pre- and postnatally were compared to no pet exposure under different birth scenarios.ResultsOver half of studied infants were exposed to at least one furry pet in the prenatal and/or postnatal periods, of which 8% were exposed in pregnancy alone and 46.8% had exposure during both time periods. As a common effect in all birth scenarios, pre- and postnatal pet exposure enriched the abundance of Oscillospira and/or Ruminococcus (P < 0.05) with more than a twofold greater likelihood of high abundance. Among vaginally born infants with maternal intrapartum antibiotic prophylaxis exposure, Streptococcaceae were substantially and significantly reduced by pet exposure (P < 0.001, FDRp = 0.03), reflecting an 80% decreased likelihood of high abundance (OR 0.20, 95%CI, 0.06–0.70) for pet exposure during pregnancy alone and a 69% reduced likelihood (OR 0.31, 95%CI, 0.16–0.58) for exposure in the pre- and postnatal time periods. All of these associations were independent of maternal asthma/allergy status, siblingship, breastfeeding exclusivity and other home characteristics.ConclusionsThe impact of pet ownership varies under different birth scenarios; however, in common, exposure to pets increased the abundance of two bacteria, Ruminococcus and Oscillospira, which have been negatively associated with childhood atopy and obesity.Electronic supplementary materialThe online version of this article (doi:10.1186/s40168-017-0254-x) contains supplementary material, which is available to authorized users.

The Role of Lung and Gut Microbiota in the Pathology of Asthma

“…During in utero development and later in life, there are several direct and indirect factors that affect healthy microbiota colonization and subsequent host-microbiota interactions. These factors include mother's health status (Stokholm et al, 2018), diet (Frei et al, 2012;Barcik et al, 2015), transfer of maternal antibodies and microbial molecules (Gomez de Ag€ uero et al, 2016;Koch et al, 2016), mode of delivery (Bosch et al, 2016), and breastfeeding and early-life environment (day care, siblings [Wolsk et al, 2016], pets at home [Sitarik et al, 2018;Tun et al, 2017], traditional farm-like dust at home [Stein et al, 2016;Kirjavainen et al, 2019], and smoking and antibiotic and other drug usage in pregnancy and early childhood [Mitre et al, 2018;Loewen et al, 2018]).…”

Influence of maternal microbiota during pregnancy on infant immunity

“…The amount of demethylated TSDR was higher with any single exposure compared with that seen after no exposure, although significantly only for maternal intake of farm milk during pregnancy [95]. Farm exposure possibly mediates epigenetic effects through changes the gut microbiota which, in turn, alters bacterial metabolites [52,96]. Regions in ORMDL sphingolipid biosynthesis regulator 1 (ORMDL1) and signal transducer and activator of transcription (STAT)-6 were hypomethylated in DNA from farmers' compared to non-farmers' children, while regions in RAD50 double-strand break repair protein (RAD50) and IL-13 were hypermethylated [96].…”

“…Importantly, the timing of these exposures is crucial, with the strongest effects observed in utero and during the first year of life [50]. While the exact mechanism of allergic protection is unclear in humans, as both prenatal and postnatal pet exposure alters infant gut microbial composition [52] it is likely that modulation of the microbiota plays a role. An interesting study by Conrad et al [51] investigated the asthma-protective effect of prenatal exposure to farm-derived microorganisms.…”

“…Intranasal exposure to Acinetobacter lwoffii F78 (cowshed-derived bacterium) protected against the development of experimental asthma in the progeny, and this protection was dependent on intact maternal Toll-like receptor (TLR) signaling [51]. While the exact mechanism of allergic protection is unclear in humans, as both prenatal and postnatal pet exposure alters infant gut microbial composition [52] it is likely that modulation of the microbiota plays a role.…”

Annual Research Review: Critical windows – the microbiota–gut–brain axis in neurocognitive development

“…Many facets of day-to-day life contribute to microbial exposure and therefore to the microbiota. Urbanization (encompassing reduced contact with the natural environment and changes in diet), pet ownership, and increasing use of antibiotics and disinfectants are all factors that alter microbial exposure and have been associated with altered microbiota (Ayeni et al, 2018;De Filippo et al, 2017;Stewart et al, 2018;Tun et al, 2017;Tun et al, 2018). well-defined for these higher order functions, at least in part due to the extended development of the supporting brain regions (Tottenham, 2017).…”