This is hardly news — it’s another feather in a pile that weighs a ton.
This battle has a lot to do with the obesity epidemic.
To be simplistic:
Bacteroidetes are “Third World” bacterial strains, more associated with an unprocessed diet. They also help to maintain a normal (or subnormal) weight, as they aren’t particularly efficient at harvesting energy
Firmicutes, on the other hand, tend to be prevalent in the guts of those eating the standard Western diet. These bacteria are highly evolved to be quite efficient at turning food into calories–and keeping it around as fat. They thrive on sugar.
Have trouble remembering these names? See this Huff Po post that reminds us that being “firm and cute” means reducing Firmicutes.
There are, however, Westerners who don’t abide by the standard Western diet. In this instance a group of Old Order Amish from Lancaster County, Pa. was studied with regard to markers for metabolic syndrome. This community was ideal for a study, having “a high degree of uniformity of genetic background, socioeconomic status, and lifestyle, which reduces potential confounders.”
Metabolic syndrome was defined in this group “by elevated BMI, blood pressure, fasting triglycerides, and fasting glucose, and low fasting HDL cholesterol.”
Stool samples were taken
from 310 adults ages 20 to 80 (64% female). Women had a higher average age and BMI and were more likely to have at least one component of the metabolic syndrome (38.9% [women] versus 26.8% [men]).
Compare this to national standard for metabolic syndrome of 35% in the general adult population [over 20] and 50% in adults over 60, with rates of metabolic syndrome higher in women than in men.
The bacterial microbiomes found in this close Amish community?
- 47% had a community dominated by Prevotella
- 39% had a community dominated by various genera from the phylum Firmicutes, most commonly Oscillospira
- 4% had a community dominated by Bacteroides.
(Prevotella is another “Third Word” bacterium. One study showed that up 53% of the gut microbiome of children in Burkina Faso was composed of prevotella. It is entirely absent in similar tests of European children.)
So, the Firmicutes outnumber the Bacteroides in this traditional diet, however, not nearly to the extent that they dominate in most Western guts.
Part of my ancestry is Pennsylvania Dutch, a community that doesn’t share the religious beliefs of the Amish, but whose traditional diet has much in common with their Amish cousins, tending to be agriculturally based, home-cooked, unprocessed, and rich in fermented foods, such as pickles and relishes. Along with these “sours,” they also love their sweets. Pennsylvania Dutch women of a certain age tend to be in shape — round is a shape, right?
Grandma did know best, it seems. Not sure if it was the “peck of dirt” or the sauerkraut. Probably a bit of both