Fitness Files: Examining the link between weight, bacteria and autism
Driving home from a weekend trip, I told my two friends, “I’m wrestling with the end of an article on the economic impact of obesity.”
“Oh, so you’re picking on poor people. Demographics show they’re the ones most often overweight,” said one. I’d barely said, “What?” and “No, I’m not,” when the other said, “You over-focus on obesity. Get another subject.”
Hey, I’m always hungry. Better to write than to overeat, correct?
Close your ears, friends, because this article got my attention. The Economist magazine, in a June article titled “Gut Feelings,” pinpoints what it calls the lesser known problem of maternal obesity. Children of obese mothers are 50% more likely to develop autism than those of normal-weight mothers, it says.
Is the biome responsible? I used to tell my fourth-grade students that the human brain was the new frontier. Now I’d add the human microbiome.
In November 2015, I wrote that “cooties are your friends,” quoting Scientific American and Economist articles detailing the role of the microbiome (gut bacteria) in harnessing energy from nutrients; regulating the density of immune cells; and protecting against some cancers, heart disease and autoimmune responses such as asthma, eczema and multiple sclerosis.
Is the microbiome a factor in autism? Full disclosure: No human trials have been performed. Still, last month’s Economist article is subtitled “The theory that bacteria are involved in some cases of autism gets a boost.”
Here’s the experiment that backs up the theory: Dr. Mauro Costa-Mattioloni and Shelly Huffington of Baylor College of Medicine controlled the diets of maternal mice. Their offspring exhibited “a clear relationship … between gut flora, obesity and social behavior.”
For eight weeks, they fed 100 pregnant mice a normal diet or a high-fat diet. Then the researchers measured how the pups interacted with strangers and inanimate objects. Researchers analyzed pup feces to identify species of gut bacteria.
Pups of obese mothers on high fat diets “tended to have problems socializing, interacting with other mice for 22 seconds during a 10-minute test, while offspring of normal-weight mothers interacted for 120 seconds. Similarly, when given a choice of interacting with an empty cup or with other mice, 55% of the pups of obese mothers preferred the cup, while 100% pups of normal-weight mothers “preferred their fellow rodents.”
Next, by analyzing pup’s feces, researchers found “lactobacillus reuteri to be nine times more abundant in pups of normal mothers.” This is potentially important because “reuteri has been shown to promote the release of oxytocin, a hormone that plays an important role in controlling mammalian social behavior.”
And here’s the great thing: Given drinking water with L. reuteri live bacteria, pups of obese mothers developed normally. Brains of pups with the drinking water cure had only 13% fewer oxytocin-producing cells than “normal pups.” Pups of obese mothers who did not receive the live bacteria in their water had 29% fewer such cells.
The Economist says that while we don’t yet know if L. reuteri plays a similar role in humans, it would be worth examining the gut flora of autistic children and their mothers.
From reading the mice studies, I gather that human tests would be noninvasive, so let’s go!
By the way, last Saturday’s Los Angeles Times’ “How your gut talks to your brain” quotes Dr. Emeran Mayer, who finds it “plausible that gut microbiota play a role in … autism” but recognizes the evidence to be speculative. Still, he says, “Five years ago, nobody had ever thought to ask [these questions].”
Now listen, readers. Years back, mothers of autistic children were absolved of causing autism by a “cold” parenting-style. I am not assigning blame because of maternal weight. However, in my final years of teaching, I observed classrooms filled with otherwise healthy, beautiful children whose educational progress was affected by their seeming inability to respond to social cues. No one could explain the sudden increase in the numbers of autistic children. If the introduction of lactobacillus reuteri could bring these children to their natural social potential, it’s worth the research.
So, do you think I’m weight-obsessed, or is today’s article worth the ink?
Note: I have read books by Temple Grandin and Daniel Tammet’s “Born on a Blue Day,” as well as many articles. I value the idea that autistic people can have insights and powers of focus unavailable to the general population.
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Newport Beach resident CARRIE LUGER SLAYBACK is a marathoner in her 70s who brought home first places in LA Marathons 2013 and 2014 and the Carlsbad Marathon 2015. She lives in Newport Beach.