Stomach Acid & Your Digestive Health | Natural Health Blog

Date: 03/13/2007    Written by: Jon Barron

Test Your Stomach Acid


After my recent newsletter about the common myths of Stomach Acid, we have had a few people ask about how to test for low stomach acid. There are actually several options. The Heidelberg Gastric Analysis test is considered one of the most accurate tests. However, it's fairly expensive (approximately $700).

The Heidelberg test involves swallowing a vitamin-sized capsule containing a pH meter and radio transmitter. You will need to fast overnight (8 hours) before the procedure, and you will drink a solution of water and bicarbonate of soda when you swallow the capsule, which normally stimulates the release of stomach acid. A computer records the readings sent by the capsule to a small medallion placed on your stomach. You will be required to recline for approximately 30-40 minutes.The fluctuations in pH are plotted on a graph, called a gastrogram. Many doctors offices that perform this test allow you the option of having the capsule removed by means of a thin attached string, or just passing it through the digestive tract and eliminating it with a bowel movement.

The Heidelberg test has been used for over 30 years. Well over a million capsules have been used to date. A major area of use is in pharmaceutical research. There have been over 143 published clinical studies with over 73 pertinent studies published since 1977.

The gastro string test is less expensive than the Heidelberg test, but not quite as accurate. The string test involves swallowing a gel capsule containing pH string. You hold one end of the string and swallow the capsule, which makes its way into the stomach where the capsule dissolves and the pH string unfolds. After 10 to 15 minutes, the string is pulled out of the stomach and out the mouth by gently pulling on the end you are holding. The end that was in the stomach is compared to a color key to measure the pH. It should be in the acid range. Neutral pH is a sign of hypochlorhydria. This may also be combined with a baking soda challenge.

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    Submitted by alan marshall on
    March 23, 2007 - 4:36pm

    hi jon, could please tell me if you have heard of RISOTREINE,stabilised rice bran. it claims to be the most nutrint dense food on earth. Is that true? and why?

    Submitted by Antonella Lewis on
    May 26, 2008 - 1:06am

    Sent me more info on Heidelberg test

    Submitted by Frances Poole on
    March 25, 2007 - 10:34pm

    I read of a test where you eat 250 grams of beetroot cooked or in juice IF YOUR URINE GOES A RED OR PINKY COLOUR, YOU ARE DEFICIENT IN HYDROCHLORIC

    Submitted by jacques on
    June 1, 2009 - 10:12am

    Hi Jon. Do you have any idea how to obtain the Gastro-Test capsules ("gastro string tests")? I used them for years but it seems the company that made them is gone.

    Submitted by Jon Barron on
    May 26, 2008 - 7:57am

    For more information on the Heidelberg test (including physician referrals), check out

    Submitted by Jon Barron on
    March 26, 2007 - 11:22am

    It's not quite as simple as that. Betalain, the red beetroot pigment, is a pH and redox indicator. It is structurally unstable at the extremes of pH, loosing its color in alkaline conditions and undergoing irreversible decomposition (to pink or yellow) in acid solution. Studies have shown that betalain is decolorized by hydrochloric acid, ferric ions and colonic bacteria preparations, but not by pancreatic or mucosal enzymes.
    However, it appears that betalain is stabilized by certain reducing agents, primarly oxalic acid. It seems that the difference between people who show red beet color in their urine (beeturia) and those who don't rests with oxalic acid in the colon. (Note: food sources of oxalic acid include parsley, spinach, and even beetroot leaves.) The more oxalic acid present in the colon, the more pigment available for absorption, which then determines if the urine will be colored. The concentration of oxalic acid will depend on the residue of the enteric oxalic acid not absorbed from the small intestine (which can vary among individuals).
    Another variable is the colonic bacterial metabolism. It has been hypothesizeded that beeturia (colored urine) can be influenced by the presence or absence of a bacterial decolorizing system. There are around 500 species of bacteria in the colon whose enzymes can be induced and have an influence on the pigments that are present in the colon.
    In the end, stomach acid does not appear to be the determining factor in having colore urine after eating beets.

    Submitted by klaus uhle on
    March 26, 2007 - 2:24pm

    I know about a crude test
    1) eat a protein rich meal
    2) swallow a tbsp apple cider vinegard
    If you feel better than you might be acid deficient and should take hcl/enzym capsules

    Submitted by michele on
    March 26, 2007 - 12:12pm

    jon,i need some help,i was given several botox shots-oculinum brand name ,i was given these for carpal tunnel neck spasms and then the neurologist gave me on around t3,t4 area of my spine, for some reason she told me to hold my breath ,she proceeded with this clear solution and within 10 mins i was in e.r. with a punctured right lung pneumothorax that was 5/4/06 a chest tube was put in to breath ,my guts shut down completely ,i had electrical currents shock my body ,my sympathetic nervous system went crazy,i was bed ridden for 5 months i could not walk lost all limb movement ,now my pituitary has shut down ,brain swelling,vision problems bladder problems etc. it effected my whole body ,i need something to get this out of my system do i do a liver clease first?? my gall bladder is having problems and i have a hepetic lesion on it -i had none of these problems before this !! my cholesterol is high

    Submitted by William "Jay" Knowles on
    November 12, 2007 - 12:06am

    I am 48y.o. and know that when I take apple cider vinegar with my meals I typically have more energy and feel better afterwards. Apple cider vinegar is great.... If you use it and feel better afterwards you probably are deficient for stomach acid. Its way cheaper than the 700$ test.

    Submitted by cristina on
    March 16, 2018 - 4:11pm
    san clemente , California

    Where can we purchase gastric pH string test?

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