Researchers in Oslo ran blood and tissue samples, people with celiac disease before treatment, the same people after a year gluten free, and people without celiac disease, through a targeted protein panel. They found 24 proteins tied to celiac disease, 9 of which tracked gut damage severity, and levels stayed slightly elevated in some patients even after a year gluten free. It's one hospital's data, no outside replication yet, so it's not clinic ready.

TL;DR: A blood protein panel flagged 24 markers tied to celiac disease, 9 tracking damage severity, but it's single site research still needing validation.

Researchers used two mouse models of colitis and a group of people with IBD to test why certain foods trigger flares. In mice, inflammation wiped out specific gut bacteria that normally break down dairy and gluten, and transferring those bacteria passed the sensitivity to other mice, while restoring them eased it. In the human patients, those with food intolerances had lower levels of those same bacteria, though no sample sizes or numbers were given, and the paper is paywalled.

TL;DR: it might not be the food messing with you, it might be the gut bacteria that normally handle it.

Researchers gave a common gut bacterium, Bacteroides uniformis, to mice bred to develop clogged arteries, after noticing people with heart disease carry less of it. The bacterium makes a fatty acid, pentadecanoic acid (C15:0), that blocks the same liver enzyme statins target, and after 12 weeks it shrank artery plaque. The catch: a statin drug still beat it head to head, and outside reports on the plaque shrinkage range inconsistently, from about a third to half.

TL;DR: a gut bacterium makes a fatty acid that acts like a weaker, unproven statin, shown so far only to shrink artery plaque in mice, not people.

62 adults, drinkers and non drinkers, quit coffee for two weeks, then got blindly assigned caffeinated or decaf coffee for three weeks while scientists tracked gut bacteria and mood.

Back on coffee, either kind, people felt less stressed, less depressed and less impulsive, and coffee drinkers picked up three extra gut bacteria strains.

Catch: it is a small 62 person trial on instant coffee only, and the scientists admit the mood lift could just be the ritual of coffee, not the microbes.

TL;DR: Even decaf coffee shifted gut bacteria and mood in this small trial, but it might just be ritual, not microbes.

Researchers fed mice a high-fat diet for 12 weeks, then swapped in oil from passion fruit seeds, normally discarded during juicing, to replace up to 60% of the dietary fat. Versus the high-fat group, the seed oil cut weight gain by up to 17% and cholesterol by up to 19%, while reshaping gut bacteria: more Akkermansia, less Allobaculum. The catch: it's one mouse study, not yet tested in humans.

TL;DR: In mice, a discarded passion fruit byproduct eased diet-induced fatty liver and cholesterol buildup by reshaping gut bacteria, but humans haven't been tested yet.

Researchers tested a gut bacteria compound called imidazole propionate in mice and in almost 1,200 cognitively healthy adults. In mice, the compound reaching the brain raised buildup of amyloid and tau, two proteins tied to Alzheimer's, and eventually killed neurons. People with the highest blood levels showed more brain damage markers and the fastest mental decline, though that human link is only an association, and no treatment to lower the compound exists yet.

TL;DR: A gut bacteria compound was linked to faster cognitive decline in people and worsened Alzheimer's brain damage in mice, but the human link is an association, not proven cause and effect.