Hallmark of Aging 12 Dysbiosis

Hallmark of Aging 12 Dysbiosis

What's dysbiosis? It essentially means the disordered distribution of bacteria in one's colonic/gut biome. It's been quite a journey, exploring the functions of our gut biome. We first knew the gut was where food went in and digestion happened. Then we added protection against dangerous bugs and parasites, and production of essential metabolites including vitamins, amino acid derivatives, neurotransmitters, secondary bile acids, and short-chain fatty acids. The amount of unique DNA in our gut biome is on the order of 100 times our own DNA, so we are really carrying around quite a treasure trove of metabolic capacity in our gut of which we are just becoming more fully aware.

Observations made on elderly humans show changes in their gut microbiome with superagers tending to substantially reduce Proteobacteria and a significant increase in Verrucomicrobia. If you transplant those bacteria with a fecal transplant into mice genetically modified to die young, they live longer. Apparently fecal transplant works, as does oral supplementation with helpful bacteria, like Akkermansia. The heterogenicity of aging biomes is daunting and still not uniform.

What is more uniform is an interesting convergence in plasma concentrations of microbiota-produced amino acid derivatives. Breakdown products like indoles from tryptophan are correlated with healthy, longer life whereas and p-cresol sulfate from phenylalanine are highly correlated with frailty and increased mortality.

Lactobacillus reuteri has been found to reduce osteoporosis. Akkermansia keeps popping up in review articles about its role in establishing a healthy gut and gut barrier, leading to better aging, better cognitive function and longer life.

What didn't make the Cell review was lactulose. Lactulose has been used for decades in Internal Medicine to salvage end-stage liver failure patients for a few more months of hopeful waiting for a liver transplant. The use of lactulose results in a massive upregulation of the healthy bifidobacteria in their gut with resulting clinical improvement in the liver failure patient's well-being. The gut essentially takes over for the dying liver, at least for a few months. The same effect happens in normal humans too. In fact, lactulose is so safe, it has now become the standard of care for pediatric constipation. Regular folks on the Standard American Diet of no fiber, saturated fat, lots of sugar are often constipated and benefit massively from lactulose.

And fiber. Dear old fiber. The more fiber one eats, the more short-chain fatty acids are made and the more diversity develops in the colonic biome. Stools become softer and more regular. Cancer risk goes down. Heart disease risk goes down. that we should all eat more fiber. Longer life (29-54% reduction in mortality).

www.What will Work for me? Akkermansia sounds like a good idea. Lactulose sounds like a no-brainer. But the cheapest and most effective of all is fiber, fiber, fiber. More green beans, fewer cookies. This whole topic is waiting for AI to sort out the complexity. I suspect what they will find is that a single meal of saturated fat and sugar will change your biome to the worse, and then gradually it will claw back. I'm annoyed the review didn't mention the biome of the tongue where Nitric Oxide is made. That may be as important as any other. Please don't use mouthwash.

References: Cell, Nature Medicine, Nature Reviews, Aging Disease, Nature Communications, Archives Internal Medicine,

Pop Quiz

1. What is our gut microbiome?                      Answer: All the variety of the 5000+ species of bacteria living in our gut.

2. What is the proportion of DNA in our gut bacteria compared to our DNA?                     Answer: around 100 to 1 gut to human. We are lucky we are the managing partner of our condo association. (Or maybe we aren't, and just don't know it yet.)

3. What is lactulose?                            Answer: An indigestible sugar to humans but a super food for bifidobacter, beneficial colonic bacteria. Bidobacter is good stuff, present in the gut of superagers.

4. Can you name a bacteria in the gut that helps reduce osteoporosis?                        Answer: Yes, lactobacillus reuteri

5. What's the cheapest way to get lots of gut diversity?                           Answer: Fiber, fiber, fiber.