A Bad Gut Feeling about Fatherlessness

Among the indicators of good infant health, one that receives relatively little attention is the presence in the neonatal gut of the right kinds of bacteria. A number of factors can affect the makeup of the microbes liv­ing in a baby’s gut, but a new study identifies family structure as a predic­tor of the relative healthiness of that makeup. Babies living in fatherless homes, it turns out, are at risk right down to their guts.

Conducted by scholars at the University of Michigan; the University of California, San Francisco; Augusta University; and Henry Ford Health System, this new study of microbes in infant guts explores an issue of underappreciated gravity. As the research team explains, “The human gut microbiome, the mixed-species community of microbes that reside in the gastrointestinal tract, plays a critical role in physiological and immu­nological maturation and homeostasis.” It is therefore predictable that when newborns experience “perturbations to gut bacterial community composition,” they subsequently face increased risk of “a variety of pedi­atric disorders,” in ways that may compromise their “childhood health status.”

To identify just what puts children at risk of developing an unhealthy gut microbiome, the researchers genetically analyze the microbiota of 298 children from a Detroit-based birth cohort. Of these children, 130 were neonates (median age of 1.2 months), and 168 were infants (median age of 6.6 months).

Statistical analyses of the data identify a number of independent predictors of the healthiness of babies’ gut microbiome. These predic­tors include maternal race-ethnicity, breastfeeding, exposure to tobacco smoke, household income, and maternal marital status. The last two items in this list might merit particular attention given the way the number of out-of-wedlock births has skyrocketed in many developed countries, including the United States, so helping to keep child poverty rates troublingly high. The researchers report that “infants of married mothers and of high-income households had… higher abundances of Bifidobacterium taxa” than did infants of unmarried mothers and of low-income households, Bifidobacteria being microbes so beneficial in the gut that they are sometimes ingested as medicine.

But in their summative analysis, the researchers identify marital status—and not household income—as part of a particularly problem­atic cluster of correlated statistical predictors of unhealthy gut micro­biota in infants. In investigating what they label as the most unhealthy of three distinctive Microbiome-associated maternal profiles (MMPs), the researchers discern a troubling conjunction of high rates for out-of-wedlock childbearing and for exposure to second-hand tobacco smoke linked to low rates for breastfeeding. Compared to mothers with either of the other two MMPs, the mothers with this most problematic MMP manifest “the highest rates of E[nvironmental]T[obacco]S[moke] expo­sure (87%) and the lowest rates of both breastfeeding (3%) and being married at delivery (20%).”

The researchers warn that children born to mothers with this MMP evince “a susceptibility profile with potentially detrimental health effects that may be mediated by early life gut microbiome composition.”

It appears that the perils that fatherless children face include invisible

but consequential ones they carry about with them in their guts.

(Albert M. Levin et al., “Joint Effects of Pregnancy, Sociocultural, and Environmental Factors on Early-Life Gut Microbiome Structure and Diversity,” Scientific Reports 6 [2016}: 31775, Web.)