Here are the likeliest culprits and how best to tackle them.
The mechanical process of digestion starts in the mouth through the act of chewing food.
Your mouth isn’t producing as much saliva.

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This can be exacerbated by medications, such as antihistamines, diuretics, antihypertensives, decongestants and alcohol.
You’re on medication.
Certain meds can also increase the risk forClostridium difficile(C. diff) colitis.
Your body’s not producing as much lactase.
There are multiple enzymes along the lining of the small intestine that are responsible for digestion of sugars.
“There can be a significant decline in lactase with aging.”
This is known as lactose non-persistence and results in difficulty digesting lactose-containing foods, such as milk and cheese.
Common symptoms of a lactase deficiency include bloating, abdominal discomfort and diarrhea after lactose ingestion.
For cheese fiends, using over-the-counter lactase supplements can also help to minimize symptoms.
Your blood sugar’s perpetually high.
The digestive tract moves in a rhythmic manner that helps propel food through the gut.
You’re running low on stomach acid.
This can lead to SIBO (small intestinal bacterial overgrowth).
Atrophic gastritis can be caused, in part, by anH.
pyloriinfection, so treating the infection can improve symptoms.
Your doctor or dietitian can then work with you on a gut-friendly diet and lifestyle plan.
Your microbiome’s out of whack.
The last component in digestion is checked off by the bacteria in the small bowel.
(Try our7-Day Meal Plan for a Healthy Gut: 1,200 Calories.)
(These are the best and worst foods for your gut health.)
Prebiotic foods are also important, since they contain fibers that help feed and fuel the good probiotic bacteria.
Enter beans, onions and garlic, bananas, artichokes and whole grains.
Also think about adding more colorful fruits and veggies to your plate, like berries, spinach and citrus.
These foods are high in fiber and keep the number-two train running smoothly.