Early-Stage Discoveries: Amino Acids, Probiotics, Krill Oil

Good results in the lab can lead to larger human trials. Here are some of the most promising recent findings.

Amino acids linked to brain health

Low-protein diets have a link to poor brain function. In the lab, mice on a low-protein diet had accelerated brain impairment, effects that reversed after supplementing with seven amino acids: leucine, phenylalanine, lysine, isoleucine, histidine, valine, and tryptophan. To find out how, doctors measured gene-level changes that revealed lower levels of kynurenine, an inflammatory factor that amino acids kept from entering the brain, preventing immune cells from attacking neurons. Amino acids also reduced neuronal death and increased neuronal connectivity.

Reference: Science Advances; 2021, Vol. 7, No. 43, abd5046

Probiotics reduce social disorders

Gut microbes appear to contribute to neurological disorders. Doctors discovered in mice, hyperactivity is controlled by genetics, but social behavior is regulated by the gut microbiome. In the lab, L. reuteri restored normal social behavior, but did not affect hyperactivity. Researchers then gave a gut metabolite that had been increased by L. reuteri to asocial mice, which improved asocial behavior.

“In my wildest dreams, I could not have imagined gut microbes could modulate behavior and brain function, but here we are,” doctors said.

Reference 3: Cell; 2021, Vol. 184, No. 7, 1740-56

Krill oil reduced inflammation in fatty tissue and liver

Obesity triggers chronic inflammation in fat tissue and in the liver. In the lab, mice had a high-fat diet with or without krill oil for 28 weeks. Levels of the omega-3 fatty acids EPA and DHA increased in all tissues in the krill oil group, with the highest concentrations in the liver. Krill oil also activated a shift towards smaller fat cells in white adipose tissue; reduced concentrations of the omega-6 arachidonic acid, and suppressed inflammatory pathways in the liver.

Reference 2: Nutrients; 2021, Vol. 13, No. 8, 2836