Does anybody know of good research which shows how long it takes the microbiome to adjust if you significantly change diet? New diets can be hard to stick with initially, and it seems like the gut's "needs" may be a real cause of this.
This was a good enough question I started researching. TL;DR: Your microbiome adapts quickly, but you don't get to see the full effects for weeks to months.
Turns out, your microbiome will shift significantly within a few days of changing your diet [0]. A more recent study showed that increasing raw vegetables in your diet significantly changed microbiome at about the same speed [1].
However, because the _effects_ of a healthy microbiome are things like better vitamin reception and disease prevention [2] [3], it can take months to see the effects of something like better B12 can take weeks to see [4]. Disease prevention of metabolic diseases takes years to see fully.
I'm a long-time serial dieter who has radically changed my diet on several occasions now, from SAD to vegitarian to SAD to vegan to SAD to raw vegan to SAD to FODMAP to SAD to McDougall high carb to paleo low carb to meat-centered to (currently) carnivore. (Among others.)
Each time (moving to non-SAD) it takes around six months before I stop naturally losing weight and either stabilize (on carnivore) or start heading back up (on everything else). I attribute this mostly to the microbiome, so by my own N=1 experiments, I'd say about six months.
As a fellow failed dieter, just trying to find something that will work for me ...
So you switch diets because you stabilize and want more weight loss, OR because they stop working? Curious to hear about the switch.
My personal preference is sugar-free. Successful for 2 years from 2016-2018, and now trying low-sugar (not no sugar) since January 2022, and reasonably successful although not much (just 6 lbs about 3%) to show for it.
I was a failed dieter from age 7 to 57. It took me that long to figure out that this body works best on animal products. I was never a particular meat eater and had to be forced to try it by an inability to move my bowels on anything else. But it has reduced and stabilized my weight like nothing else has, while all but eliminating my cravings for SAD food. I really like eating this way now, and get as much or more pleasure from food than ever.
When I switched it was in despair over failure. They all (but the last) stopped working, though I continued to follow them religiously. For years I was an obsessive food diarist, and have books full of logs on what I ate, with charts showing how my weight gradually stabilized well before goal, and started going up again. This followed the trend of my appetite. When I switch diets my appetite goes down, and it recovers gradually over that half-year.
I think going sugar-free is a great move, but from sources like https://high-fat-nutrition.blogspot.com/ have come to think that avoiding seed-oils is even more important, over a span of decades.
There is general research that shows that after about two weeks of limited inputs, bacteria colonies will go dormant, retreating into the structural matrix ("slime") that bacteria produce for themselves. If fed, they will come roaring back relatively quickly. To mostly kill off a species of bacteria, it can take months (6-ish?) of starving them during their dormant state. Sorry, no links, just reporting recollections from general reading that I have been doing.
Stop reading now unless you are interested in cardio-vascular disease.
I started researching this a little over a year ago when I got a cardiac stent to prop open a 99% blockage in the left anterior descending artery. Yeah, I was probably within weeks of having the classic widow-maker heart attack. (I didn't, and I'm now fit and healthy, so I consider myself lucky.) I eventually found a line of research out of the Cleveland Clinic, work done by Dr. Caldwell Esselstyn. His work is based on this: 1. CVD is the result of an injury to the endothelium that first attracts white blood cells to the damage, then cholesterol joins the party and they form "foam" cells that can get under the endothelium and eventually calcify. 2. The endothelium produces Nitric Oxide gas that is both a vaso-dialator and also helps the endothelium repair itself and cleanse itself of non-calcified foam cells. 3. The primary driver of CVD that is associated with the standard American diet is that the diet destroys the Nitric Oxide blood gas.
How does that destruction of Nitric Oxide happen? 1. Carnitine, lecithin, and other proteins found in meat, fish, diary, and oils are metabolized by a colony of gut bacteria to produce tri-methyl amine (TMA). 2. TMA travels to the liver and is metabolized into tri-methyl amine oxdide (TMAO). 3. TMAO enters the blood stream and annihilates nitric oxide, robbing the endothelium of its self-defense mechanism. Eating a meal that feeds that bacteria colony will suppress nitric oxide blood gas for 6 to 8 hours. So, if you eat the SAD at every meal, the level of nitric oxide will never recover.
I am on a mission to starve those little bacteria bastards out. Kill'em all with gleeful murder in my heart. So for about a year I have been on a diet that is most easily described as vegan, with the additional restriction of no oils and high-oil foods. I wish I had some good way of measuring my blood TMAO levels. I don't, so I'm just going by the general rule of being as strict as possible for several months to try to knock the bacteria out as best as I can.
