By Stefan Ianev
Gut health is a hot topic these days. Although this is a complicated area and it is beyond the scope of a personal trainer or fitness professional to diagnose or treat clients with serious digestive or gut issues, it is still important to understand the basics of how the digestive system works, and how to optimize digestion through good nutrition and basic supplementation.
Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion such as the pancreas, liver, and gallbladder.
Figure 1. From start to end the gastrointestinal tract is about 25 feet in length
The stomach is the first major stage of digestion and will be the focus of part 1 of this article. The stomach secretes hydrochloric acid (HCL) which serves several important functions.
Firstly, hydrochloric acid kills off and prevents harmful bacteria from entering the small intestine. We are going to talk more about how this compromises gut health in part 2 of this article.
Secondly, hydrochloric acid also activates pepsin, a proteolytic enzyme which breaks down proteins into smaller amino acid chains called polypeptides. Therefore, protein digestion is initiated in the stomach. Hydrochloric acid also stimulates the release of pancreatic enzymes and bile into the small intestine which is required for the digestion of carbohydrates and fats.
Lastly, hydrochloric acid is required for the absorption of several vitamins and minerals including iron, zinc, calcium carbonate, beta-carotene, folate, vitamin B12, and vitamin C (1-11).
Low stomach acid secretion, called hypochlorhydria has been linked to numerous metabolic and health conditions including:
- Gallbladder disease (13)
- Alcoholism (14)
- Skin diseases (10,32)
- Arthritis (15,16)
- Osteoporosis (17,18)
- Diabetes (219-22)
- Asthma (23,24)
- Hypo or Hyperthyroidism (25,26)
- Anemia (19)
- Bacterial overgrowth an infection (7,9,12,19,27,28,29,30)
- Stomach cancer (30)
- Depression (31)
Many of these conditions have been shown to be reversed or drastically improved when hydrochloric acid levels were normalized following hydrochloric acid supplementation (18,10,11,12,19,23,30,32).
Numerous studies have shown that hydrochloric acid secretion declines with age (30,33,34,35). In fact, it is estimated that 30-40% of adults over 50 years of age suffer from achlorhydria, which is the complete absence of stomach acid secretion.
Other causes of hypochlorhydria include vitamin B deficiency, H. pylori infection, chronic overeating, hypoadrenalism, chronic stress, excess intake of processed foods and carbohydrates, caffeine, alcohol, hypoglycaemia, and undereating (14,36,37,38,39,40).
A variety of signs and symptoms can suggest decreased stomach acid secretion including:
- Bloating or prolonged fullness after meals (23,30)
- Diarrhea or constipation (19,23,30)
- Flatulence after eating (23,30)
- Heartburn and indigestion (23,30)
- Food allergies (5)
- Nausea after taking supplements (23,30)
- Soreness, burning, and dryness of the mouth (30)
- Glossitis – inflammation of the tongue (30)
- Undigested food in stools (23)
- Weak, pealing and cracked fingernails (23)
- Hair loss in women (23)
Notice that many of the symptoms above are related to Gastroesophageal Reflux Disease (GERD). GERD, or acid reflux, occurs when the lower oesophageal sphincter does not close properly, allowing stomach acid to pass back up into the oesophagus.
The most common treatment for GERD is proton-pump inhibitors (PPIs), a class of drugs which suppress stomach acid secretion. While these drugs are effective at masking the symptoms related to GERD, they do not address the underlying cause, and long term they can end up exacerbating the problem if used too frequently or for too long.
That is because the tightness of the lower oesophageal sphincter is in part regulated by the acidity of the stomach. When the acidity in the stomach increases, the lower oesophageal sphincter responds by contracting more tightly (41-43).
Therefore, a high amount of hydrochloric acid in the stomach, which is a normal and healthy part of digestion, actually prevents GERD or acid reflux by stimulating the lower oesophageal sphincter to close tightly, preventing stomach acid from passing back up into the oesophagus.
PPI medications have been linked to increased risk of many health conditions including vitamin and mineral deficiencies, gut infections, pneumonia, osteoporosis and hip fractures, small intestinal bacterial overgrowth, gastric tumours and cancer, infections outside the GI tract, dementia, and chronic kidney disease (44-50).
There are functional approaches for diagnosing hypochloridria. One such test that we have used for years at CHFI is the HCL challenge test. The HCL challenge test involves taking an escalating dose of betaine HCL capsules immediately after meals until a mild burning sensation in the stomach is felt, or a maximum dosage is reached (51,52).
Instruction for the HCL challenge test are as follows:
- Immediately after a meal when your normal digestive processes have started take a 200mg tablet or capsule of betaine HCL.
- If no burning sensation in the stomach is felt 10 to 15 minutes after the meal, then proceed to take two HCL capsules at your next meal.
- If no burning sensation is felt again then proceed to take three HCL capsules at your next meal.
- Continue this process until you feel a mild burning sensation in your stomach, or you reach a maximum of seven capsules.
If you felt the mild burning sensation after only one cap, then most likely you are producing enough hydrochloric acid on your own. If the burning sensation is too uncomfortable just drink a glass of water with a table tablespoon of baking soda. Baking soda is a mild base and will neutralize the hydrochloric acid.
If you felt the burning sensation after two to four caps, then you may have a mild hydrochloric acid deficiency, and if you if felt the burning sensation after five to seven caps or not at all, that is considered a sign on hypochloridria. In that case consider taking a supplemental dose of HCL with each meal one capsule below the dose at which you felt the burning sensation.
If you need to take more than three capsules as a supplemental dose, then considering purchasing 500 to 600mg capsules to avoid having to swallow so many pills at once. HCL supplementation is generally more effective when taken in conjunction with pepsin and gentian. Gentian is a herb which acts on taste bud receptors to stimulate the secretion of saliva in the mouth and hydrochloric acid in the stomach (53).
Hopefully, you can now appreciate the importance of hydrochloric acid in good digestive health. Hypochloridria should always be considered in clients presenting with digestive issues or any of the symptoms listed above as the first line of intervention against poor gut health.
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