Author and alternative medicine advocate Deepak Chopra once said: "... when you say, 'I have a gut feeling'... you're not speaking metaphorically. You're speaking literally." And now a study published in the journal Frontiers in Psychiatry has proof.

Researchers explored the connection between loneliness and biology and found that diversity — or lack of diversity — in your gut microbiome influences and is influenced by feeling lonely.

The researchers compared fecal samples from volunteers ages 28 to 97 with their self-reported measures of loneliness, social support, and social engagement.

It turned out that people who are lonely are more likely to have an unstable gut biome. That reduces their resistance to and resilience to stress-related disruptions and disease.

Stress-related disruptions and disease can lead to bodily changes that evoke feelings of isolation. The feedback loop between loneliness and gut disruption is complete.

Whichever comes first — lack of gut biome diversity or loneliness — the two are connected through the "gut-brain axis" that links your gastrointestinal system to emotional and cognitive centers of the brain. The gut and brain talk to each other through neural activity, hormones, and the immune system.

If you want to feel less lonely, cultivate a diverse gut biome by eating a diet full of prebiotics and probiotics. Also stop eating gut-damaging ultra-processed foods, red meats, and added sugars — and consider taking a daily probiotic.

Conversely, if you want your gut to feel better, reach out to friends and family and volunteer to help others.

Defeating loneliness (and the physiological changes it brings) may nurture a healthier gut biome.