The Importance of Bacteria to Immunity and Barriers

  I just read a fascinating article here about the ongoing research of the so-called ‘human microbiome’, or gut flora in other words. There is some stunning research going on in this area, in the development of probiotics and even transplanting healthy faecal matter containing bacteria, viruses, fungi and all manner of things into unhealthy people to ‘re-set’ their immune systems if you like.

One thing I thought was particularly interesting is what they found happens in pregnant women specifically to help babies digest the breast milk when they are born. As a species, we aren’t really able to digest milks well as we lack the lactase enzyme production but Nature helps out particularly in the early stages. This is why many babies can tolerate breast milk but not cow’s milk formulas and allergy problems start to appear not long after the introduction of the formula:

A number of recent reports shed light on how mothers promote the health of their children by shaping their microbiomes. In a study published last week in the journal PLoS One, Dr. Kjersti Aagaard-Tillery, an obstetrician at Baylor College of Medicine, and her colleagues described the vaginal microbiome in pregnant women. Before she started the study, Dr. Aagaard-Tillery expected this microbiome to be no different from that of women who weren’t pregnant.

“In fact, what we found is the exact opposite,” she said.

Early in the first trimester of pregnancy, she found, the diversity of vaginal bacteria changes significantly. Abundant species become rare, and vice versa.

One of the dominant species in the vagina of a pregnant woman, it turns out, is Lactobacillus johnsonii. It is usually found in the gut, where it produces enzymes that digest milk. It’s an odd species to find proliferating in the vagina, to say the least. Dr. Aagaard-Tillery speculates that changing conditions in the vagina encourage the bacteria to grow. During delivery, a baby will be coated by Lactobacillus johnsonii and ingest some of it. Dr. Aagaard-Tillery suggests that this inoculation prepares the infant to digest breast milk.

The baby’s microbiome continues to grow during breast-feeding. In a study of 16 lactating women published last year, Katherine M. Hunt of the University of Idaho and her colleagues reported that the women’s milk had up to 600 species of bacteria, as well as sugars called oligosaccharides that babies cannot digest. The sugars serve to nourish certain beneficial gut bacteria in the infants, the scientists said. The more the good bacteria thrive, the harder it is for harmful species to gain a foothold.

How fascinating. Another interesting point came up about barriers:

One way to restore microbiomes may be to selectively foster beneficial bacteria. To ward off dangerous skin pathogens like Staphylococcus aureus, for instance, Dr. Segre envisions applying a cream infused with nutrients for harmless skin bacteria to feed on. “It’s promoting the growth of the healthy bacteria that can then overtake the staph,” she said.

I have often wittered on about the importance of the skin barrier and stated my belief that allergy reactions like eczema and dermatitis are due to a broken, hyper-permeable skin barrier. (And don’t get me started about the various creams containing barrier-breakdown chemicals in them that people slather over themselves several times a day to help relieve it…! See my article on this subject, Thinny Skinnieshere.)

Anyway, this comment struck me as what we are actually trying to do with our internal barriers. With the Barrier Plan protocol, part of what we are trying to achieve is to replace some of the lost microbiome – the baby probiotics are important here for a start – and to provide the nutrients for the inner skin to heal, partly by providing the right nutrients for the skin bacteria to feed on. Not so different to external skin, is it? I feel pleased with myself; we are attempting to apply an inner skin cream!

The article goes on to talk about the developing research – there are thousands of species coming to light including some viruses and fungi we tolerate and live with day in day out. The faecal transplant stuff is yielding a lot of info and hope – but the focus is on producing specific probiotic pills to save having to do the full poo transplants, thank goodness:

Dr. Alexander Khoruts of the University of Minnesota and his colleagues want to make fecal transplants standard practice. They can now extract bacteria from stool, “removing the ‘ick’ factor,” as he puts it.

Dr. Khoruts and his colleagues have federal approval to start formal clinical trials on fecal transplants. Eventually, he would like to develop probiotic pills that contain just a few key species required to build the intestinal ecosystem.

“People are starting to take this seriously,” Dr. Fischbach said. “This is a therapy that’s going to help a lot of people.”

I would echo that. Probiotics may need a lot more developing yet but, in nutritional medicine, we have been saying stuff along these lines for many years now. We just need the scientists to be funded now to move it forward to mainstream acceptance. A fascinating area of science, or is it just me because I like anything bowely? :)

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