Can this Gene Cause Indigestion? (NOS1)

Giving Up Smoking

In a study on 32 people diagnosed with bowel cancer, those who smoked had lower NOS1 levels and NO production in their blood vessels. A study of mice chronically exposed to cigarette smoke found similar results [R, R].

Cigarette smoke also activates the enzymes (arginases) that take away the fuel (arginine) used by NOS enzymes to create NO [R]. 

In addition, smoking has been associated with an increased incidence of upper digestive disorders such as indigestion and GERD [R, R].

Whether you have digestive issues or not, abandoning this habit will certainly improve your overall health.

Exercise

Exercise increased NOS1 production and activity in the muscles of humans and rats [R, R, R].

Adding to its numerous health effects, moderate exercise improved stomach emptying in a trial on 30 people while physical inactivity has been associated with indigestion [R, R].

Avoiding Excess Alcohol

In rats and mice, chronic consumption of alcohol lowered the production of NOS1 in the digestive system by increasing the death of the nerve cells involved in this process. It was also associated with reduced muscle relaxation [R, R, R].

While moderate alcohol consumption hasn’t been clearly associated with digestive disorders, its abuse may cause and worsen them, especially indigestion [R].

Everyone has a different threshold of alcohol that is healthy for them. If you’re experiencing digestive issues, we recommend cutting alcohol out if you have negative NOS1 genetic variants. 

Giving up smoking, doing moderate exercise, and drinking less alcohol may increase NOS1 activity while reducing gut inflammation.

Avoiding Trigger Foods

Many people report that certain foods either aggravate or alleviate their indigestion symptoms. If you experience symptoms after eating certain foods, we recommend discussing these foods with your doctor. You may then be advised to avoid them, or at least to keep a meal diary to track the intensity of your symptoms relative to the foods you eat [R].

Some reported trigger foods include [R]:

• Carbonated beverages (soft drinks)
• Coffee
• Legumes (beans, lentils)
• Processed meat (sausage, cured meat)
• Beef
• Pasta
• Oranges
• Onions
• Mayonnaise
• Cabbage
• Whole grains

Avoiding fatty foods may be especially beneficial, since high-fat diets caused the death of NOS1-producing nerve cells and reduced digestive motility in animal studies [R, R, R, R].

Foods Rich in NO Precursors

Watermelon is very rich in the non-essential amino acid citrulline, which the body can use to make NO’s precursor arginine. Other citrulline sources include melons, pumpkins, and cucumbers. More directly, arginine-rich foods include chickpeas, peanuts, soybeans, lentils, turkey, or pork loin [R, R, R].

Similarly, foods that contain nitrates can potentially increase nitric oxide. Nitrates get converted to nitrites, which are then converted into nitric oxide in the body. Vegetables are rich in nitrates and roughly supply 80% of these compounds [R]. 

Beetroot is the most famous nitrate-rich food. Some other nitrate sources include [R]:

• Leafy greens
• Celery
• Broccoli
• Chinese cabbage
• Turnips
• Cucumbers
• Carrots
• Cauliflower
• Pomegranate juice

Avoiding possible indigestion triggers and eating foods that supply building blocks for NO production may help reduce indigestion in people with NOS1 underactive variants.

Methylfolate and Vitamin C

Tetrahydrobiopterin (BH4) is essential for the function of NOS enzymes. In a few studies, middle-aged and elderly people who took BH4 had improved vasodilation and circulation, which the authors attributed to NOS3-derived NO [R, R].

In rats, BH4 promoted stomach emptying by stimulating NOS1 activity [R, R].

Supplements that could increase BH4 availability, such as methylfolate and vitamin C, are promising subjects for additional research [R, R].

Probiotics

The probiotic strain Lactobacillus fermentum relieved stomach injuries caused by alcohol in mice, at least in part by increasing NOS1 activity. This microbe also relieved digestive conditions such as IBD and constipation [R, R, R].

Prodefen Plus is a commercial probiotic with different species of Lactobacillus (L. rhamnosus, L. casei, L. acidophilus, and L. delbrueckii), Bifidobacterium (B. breve and B. longum subsp. infantis), and Streptococcus (S. thermophilus). 

In rats with metabolic syndrome caused by a high-fat diet, the probiotic lowered blood pressure by restoring NOS1 activity. In a clinical trial on 85 children with viral diarrhea, Profeden Plus enhanced the effectiveness of the treatment [R, R].

Probiotics are being investigated as a new strategy to restore imbalances in the gut microbiota that may impair intestinal function and cause indigestion [R].

Herbal Supplements

In rats and mice, the following herbal supplements prevented digestive conditions such as stomach injuries, constipation, and even cancer by increasing NOS1 activity:

• Quercetin [R, R]
• Red sage (salvianolic acid A) [R]
• Cape jasmine [R]
• Kuding tea polyphenols [R]
• Aloe vera [R]

Note, however, that none of them has been proven to boost NOS1 activity in humans.

Probiotics, substances that increase BH4 availability, and some herbal supplements may reduce digestive issues by increasing NOS1 activity. However, more clinical research is needed.