Your Gut at 60, 70, and Beyond: How Aging Changes Digestion — and What You Can Do About It

If your stomach handles food differently than it did at 30, you are not imagining it. The entire digestive tract — from the moment you swallow to the final stages of elimination — shifts with age. The good news is that much of what changes is within your control. A few steady habits can keep your gut comfortable, regular, and resilient for decades.

Here is what actually happens as the years add up, and the practical, science-backed steps that make the biggest difference.

What changes along the whole tract

Digestion is a long assembly line, and aging touches nearly every station.

In the oesophagus, the muscular squeezing that pushes food downward weakens slightly, and the valves at the top and bottom lose some of their tone. Food still gets where it needs to go, but reflux and heartburn become more common — partly because that lower valve no longer seals as tightly.

In the stomach, two things tend to shift. The lining becomes less able to protect itself, which raises the risk of ulcers, especially for people taking anti-inflammatory painkillers like ibuprofen. Many older adults also produce less stomach acid, which can make it harder to absorb certain nutrients, including vitamin B12, iron, and calcium.

In the colon, muscle contractions slow down. When waste moves more slowly, the body pulls more water out of it, leaving stool harder and drier. This is a major reason constipation becomes so common — roughly one in three older adults deals with it.

The hidden organ: your gut microbiome

The most important age-related change may be invisible. Your digestive tract is home to trillions of bacteria, collectively called the microbiome. This living community helps digest fibre, makes vitamins, trains your immune system, and protects against harmful invaders.

As we age, this community tends to lose diversity — fewer different species call your gut home than when you were younger. Helpful, anti-inflammatory bacteria such as Bifidobacteria and Faecalibacterium often decline, while less friendly species gain ground. Researchers have linked a less diverse microbiome to constipation, a weaker response to infection, obesity, frailty, and even neurological conditions like Parkinson’s disease.

A thinning microbiome also feeds what scientists call “inflammaging” — a low, persistent level of inflammation that rises with age and contributes to many chronic diseases.

Strikingly, studies of people who live past 100 find their gut bacteria stay unusually diverse, suggesting that a rich microbiome is part of healthy aging rather than just a casualty of it.

The relationship runs both ways: an aging gut becomes a less hospitable home for good bacteria, and the loss of good bacteria makes the gut age faster. That two-way street is also why everyday habits have real power to tip things in your favour.

Six things that genuinely help

1. Eat fermented foods regularly. This is one of the most promising findings in recent gut research. In a Stanford clinical trial, people who ate more fermented foods for ten weeks saw their microbiome diversity increase and their markers of inflammation drop. Yogurt with live cultures, kefir, sauerkraut, kimchi, miso, and other naturally fermented foods deliver live microbes that fibre alone can’t. Aim to work a serving or two into your day.

2. Feed your bacteria with fibre and plants. Fibre is the fuel your good bacteria use to produce anti-inflammatory compounds, and it keeps stool soft and moving. Build meals around vegetables, fruit, whole grains, beans, lentils, nuts, and seeds. Variety matters as much as quantity — different plants feed different bacteria, so a colourful, mixed plate supports a more diverse gut. Increase fibre gradually to avoid gas and bloating.

3. Drink enough water. Fibre works best with fluid. Without it, more fibre can actually worsen constipation. Sip throughout the day; don’t wait until you feel thirsty, since the sense of thirst itself fades with age.

4. Keep moving. Regular physical activity is consistently linked to a richer, healthier microbiome in older adults — and it physically helps move waste through the colon. You don’t need to be an athlete; reviews show benefits across all fitness levels. A daily walk, gardening, swimming, or light strength work all count.

5. Review your medications. Many common drugs affect digestion. Frequent use of acid-reducing medications, certain painkillers, and some blood pressure or pain treatments can slow the gut, alter the microbiome, or affect nutrient absorption. Don’t stop anything on your own, but do ask your doctor or pharmacist to review your list periodically.

6. Protect your stomach lining. If you take anti-inflammatory painkillers often, talk to your doctor about safer options or stomach-protecting strategies, and take them with food. Limiting alcohol and not smoking also reduce reflux and ulcer risk.

When to see a doctor

Some symptoms deserve prompt attention rather than home remedies. See a healthcare professional for difficulty or pain when swallowing, unintended weight loss, blood in the stool or black stools, persistent vomiting, a sudden change in bowel habits that lasts more than a couple of weeks, or ongoing abdominal pain. These can be signs of conditions that are very treatable when caught early.

The bottom line

Aging changes your digestive system, but it doesn’t have to mean discomfort. The same simple habits — fermented foods, plenty of plants and fibre, water, movement, and a smart look at your medications — support both the machinery of digestion and the trillions of bacteria that keep it humming. Start with one change this week. Your gut, and the rest of you, will feel the difference.

This article is for general information and isn’t a substitute for personalised medical advice. Talk with your doctor about your own situation, especially before changing medications or starting a new exercise routine.