A MICROSCOPIC VIEW OF THIS CHAPTER
• Gastric reflux can be due to a variety of problems.
• A bacteria, H. pylori, is a major cause of gastric reflux.
• H. pylori can cause ulcers and stomach cancer.
• Probiotic species can help fight an H. pylori infection.
• Ulcers may heal faster in the presence of probiotics.
It burns. It hurts. Gastric reflux, more commonly known as heartburn, is an uncomfortable problem affecting many adults. Gastric reflux is a condition in which the liquid content of the stomach regurgitates (moves up toward the mouth) into the esophagus. The stomach’s liquid contents can inflame and damage the lining of the esophagus. This is because the regurgitated liquid contains acid and pepsin. Pepsin is an enzyme that digests proteins in the stomach, and as such it can digest proteins in the esophagus. Acid is believed to be the most harmful component of the refluxed liquid, although damage to the esophagus from gastric reflux only occurs in a small number of people.
HOW DO YOU DEVELOP GASTRIC REFLUX?
Gastric reflux can be the result of a number of factors:
• Gallstones, which can prevent the flow of bile into the small intestine and in turn can affect your ability to neutralize gastric acid from the stomach.
• Not enough acid production in the stomach prevents the stomach from emptying and encourages stomach contents to move up into the esophagus.
• Hiatus hernia—a weakness in the diaphragm allows the stomach to move up toward the throat—which increases the chances of gastric reflux.
• Zollinger-Ellison syndrome, which increases gastrin production, causing the stomach’s acidity to increase.
• Hypercalcemia, which can also increase gastrin production, leading to increased acidity.
• Scleroderma and systemic sclerosis, which can reduce the proper movement of the esophagus (throat).
• Helicobacter pylori, a bacteria, which is commonly found in people with gastric reflux.
Many of these factors cannot be easily fixed. Acid production in the stomach can be influenced by the types of foods you eat, how fast you eat and how much you eat. Probiotics can help fight one cause of heartburn—H. pylori infections.
HELICOBACTER PYLORI: THE GASTRIC REFLUX BACTERIA
The gastric bacterial pathogen, Helicobacter pylori, is the main cause of stomach ulcers and a major risk factor for stomach cancer. Gastric reflux patients are commonly screened for H. pylori infections as this bacteria is a common cause.
Helicobacter species are the only known microorganisms that can thrive in the highly acidic environment of the stomach. It has a helical shape, from which the genus name is derived. Helicobacter pylori has a unique shape that helps it penetrate the mucus layer of the stomach. The helical shape also gives it superior motility in the stomach. Helicobacter pylori will live in many areas of the stomach. Its presence can result in the formation of an ulcer. An ulcer is an open sore which is unable to heal due to ongoing infection or inflammation. Ulcers in the stomach can bleed and cause other complications. Ulcers can also be caused by the use of non-steroidal anti-inflammatory drugs such as ibuprofen.
Are All H. pylori Strains Bad?
There are many strains of H. pylori. Some appear to offer significant benefits to their human hosts, while others can cause negative effects in your stomach. Different H. pylori strains have been identified. Each H. pylori has a different negative effect on your health, and each can affect different parts of your intestines. For example, in Western countries, a person with one type of H. pylori (cag+, s1a vacA, iceA1 strain) is more likely to develop ulcers in his or her small intestine than a person harboring a different strain (cag-, s2 vacA, iceA2). In the future, more knowledge of H. pylori strains could help to identify people at risk of particular diseases.
H. PYLORI AND CANCER
An H. pylori infection can cause gastric reflux, ulcers and cancer. How is H. pylori associated with cancer? One of the known reasons for the association is the decreasing incidence of gastric cancer in North America. In fact, gastric cancer has decreased 80% from 1900 to 2000. The incidence of H. pylori infections in humans has also decreased in developing countries where sanitation and antibiotics are used effectively. This drastic decrease in gastric cancer rates where there has been a decline in H. pylori infections is consistent with epidemiological links between gastic cancer and this bacterium. Consequently, H. pylori has been categorized as a carcinogen by the International Agency for Research on Cancer.
Of patients who are not taking non-steroidal anti-inflammatory drugs, 95% of the cases of duodenal ulcer will be due to an H pylori infection.
How does H. pylori cause cancer? Despite the direct causal relationships noted, researchers are not yet sure how H. pylori causes gastric cancer. There are two theories currently under investigation. First, H. pylori might increase the production of free radicals, which can cause damage to the cells in the stomach. The damage can occur to cell DNA, which in turn can lead to cancer. Second, H. pylori may cause changes to stomach cells in a way that helps cancer grow. The bacteria might change a cell’s phenotypes, such as cell proteins, giving a cancer cell the structure it needs to grow.
PROBIOTICS FOR H. PYLORI
As it is a bacteria, antibiotics are the most common treatment used in patients with an H. pylori infection. However, as we’ve seen, antibiotic use kills good bacteria in the body, reducing your immune health as well as your overall health. In addition, antibiotic resistance is a major problem. Antibiotic-resistant bacteria do not react to antibiotics. A growing number of antibiotic-resistant bacteria has increased the need for medical practioners to find alternative methods to get rid of an H. pylori infection in the intestinal tract. Probiotics may be an effective way to treat an H. pylori infection. Or perhaps probiotics are a good addition to antibiotic treatment. When probiotics are combined with antibiotics there is an increase in the cure rate of the infection. As well, there is a reduced rate of side effects from the antibiotics when probiotics are taken concurrently.
Can You Take Probiotics with Antibiotics?
Yes, the evidence supports the concurrent use of probiotics and antibiotics. Antibiotics are effective bacterial killers. As such, they can rid the body of invading pathogenic bacteria. Taking probiotics concurrently will ensure the natural microflora is maintained, which in turn ensures the health benefits elicited by probiotics are still occurring—in particular, probiotics’ ability to boost immune health. However, probiotics and antibiotics should not be taken at the same time, as the antibiotic may destroy some of the ingested probiotics. Separating their administration by four hours is suggested.
Most of the clinical trials that have investigated the use of probiotics to fight Helicobacter infections have found that probiotics have a positive result. The use of many species of probiotics have been investigated in people infected with H. pylori. Both Lactobacilli and Bifidobacterium strains have been shown to be effective against this nasty bacteria. As with most illnesses, no one probiotic species appears to be superior to others at eradicating H. pylori. Let’s look at the science.
In a randomized, placebo-controlled study, Lactobacillus acidophilus was given to volunteers with H. pylori infections in addition to their pharmaceutical medications. The study reported an 87% eradication of H. pylori with probiotic use versus 70% in the control group. Lactobacillus brevis CD2 also induced a reduction in H. pylori in a similar clinical study.
Other Lactobacilli species have been found in studies to eradicate H. pylori infections in the stomach. Lactobacillus casei Shirota reduced H. pylori in about 64% of the volunteers in a study, compared to only 33% of those not receiving the probiotic. Lactobacillus gasseri OLL2716 was effective in two research studies at reducing the number of H. pylori in the intestinal tract of adults, but not in children.
Lactobacillus johnsonii La1 has been investigated in three trials. This probiotic can increase mucus thickness and reduce inflammation in the intestinal tract, which are both great benefits to your stomach’s health. However, L. johnsonii La1 did not decrease H. pylori in the stomach in these studies. Its other benefits to stomach health may make it a good probiotic to include in a multi-probiotic species supplement targeting stomach health.
The Lactobacilli species with the most promise to treat H. pylori infections is Lactobacillus reuteri. In a clinical trial, Lactobacillus reuteri ATCC 55730 (L. reuteri) was given to 30 adults suffering from heartburn due to an H. pylori infection. Twice daily for 30 days, the adults took their assigned treatment of either omeprazole (a pharmaceutical that reduces heartburn symptoms) and L. reuteri or omeprazole alone. H. pylori was eliminated in the adults taking the L. reuteri, but not in the group only taking the drug. L. reuteri supplementation also reduces side effects of drugs used to kill H. pylori in children. In a cross-over, randomized double-blind clinical trial performed in Japan, supplementation with L. reuteri reduced the level of H. pylori infection by 20% to 30%. Additional research from Italy found that L. reuteri improved symptoms of abdominal pain, reflux, indigestion, diarrhea and constipation in people suffering from H. pylori infections.
Why is L. reuteri so effective against H. pylori? L. reuteri is able to survive better in the stomach than most probiotic strains. L. reuteri colonizes the stomach and upper duodenum, all of which are sites of H. pylori infection. Also, L. reuteri produces a compound called reuterin (3-hydroxy propionaldehyde) that kills microbes (an antimicrobial). Reuterin may prevent H. pylori from living in your stomach. L. reuteri also has a protein on its surface that allows it to attach to the same places H. pylori likes to attach in the stomach. This means fewer places for H. pylori to attach and grow. This is called competitive inhibition. It means that the probiotic competes against the bad microbes for the same things (e.g., receptor sites, nutrients, space) making it hard for the bad microbe to live in you.
PROBIOTIC COMBOS FOR FIGHTING H. PYLORI
Is a combination of probiotics better at fighting H. pylori than a single probiotic? In a study, a combination of L. rhamnosus and S. boulardii was compared to a mixture of Lactobacillus and Bifidobacterium strains. Both probiotic mixtures were superior to the placebo (no probiotics) at making people feel better and reducing the amount of H. pylori in the stomach; however, neither eliminated the H. pylori infection.
A combination of Lactobacilli has similar results. When another study used L. johnsonii La1, L. acidophilus LB and L. rhamnosus GG in conjunction with drugs, they were effective at reducing H. pylori levels in the stomach.
A probiotic combination containing L. acidophilus La5 and B. lactis Bb12 was shown to significantly decrease the number of bacteria and the amount of acid in the stomach in people infected with H. pylori. Again, it did not eliminate the infection.
Of note, a combination of a Lactobacilli and yeast was found to be better at reducing H. pylori than the Lactobacilli-Bifidobacterium combination noted above.
It appears that many species of probiotics have beneficial effects to the stomach and reduce the amount of H. pylori. Even in the presence of drugs, probiotics help treat an H. pylori infection. Which combination is likely best? Each probiotic species offers a different set of health benefits. Many species help fight H. pylori infections. It is likely that a combination of multiple species and strains of probiotics will offer the best attack against H. pylori infections.
H. PYLORI: A SILENT INFECTION
Some people are infected with H. pylori and do not know it. They do not show any symptoms of disease. Helicobacter pylori infections affect about half of the world’s population. They are particularly prevalent in Asia. Although it is a common infection, it is not a gentle one. Ulcers of the stomach and small intestine can develop over time if this bacteria is allowed to live in the stomach without inhibition by probiotics or other treatments. The most drastic consequences of an H. pylori infection is stomach cancer. Obviously, individuals who do not show any symptoms of the infection are most at risk. Since reducing the amount of H. pylori in the stomach may reduce the risk of stomach cancer, adding probiotics to everyone’s daily diet might help reduce the risk of stomach disease in people with undetected H. pylori infections.
PROBIOTICS FOR ULCERS
Once an H. pylori infection is treated, the stomach lining can be in bad shape. Sores on the intestinal lining, or ulcers, can persist. Do probiotics have any beneficial effects in treating ulcers? Animal research has found that Lactobacillus rhamnosus GG can help stomach ulcers to heal. A daily dosage of 108 CFU of L. rhamnosus GG for three days after an ulcer has formed can speed the rate at which the ulcer heals. L. rhamnosus GG is capable of living in the stomach, particularly in areas where ulcers occur. Research suggests that L. rhamnosus GG helps ulcers heal by beneficially encouraging damaged cells to die (apoptosis) and new cells to grow (cell proliferation), as well as by promoting the growth of new blood vessels (angiogenesis) to help the tissue heal. Other probiotic species may also offer some help in ulcer healing, but more research is needed. It is likely that these species will be of the Lactobacilli family as they naturally inhabit the stomach.
SUMMARY
Helicobacter pylori is a bacteria that likes to colonize in the mucus of the stomach. H. pylori is commonly found in humans and is strongly associated with heartburn (gastritis), ulcers (duodenal and gastric) and stomach cancer. Several probiotic strains, especially Lactobacilli, have been shown to inhibit H. pylori growth and infection in the stomach. Many species of Lactobacilli appear to cause beneficial effects in individuals infected by H. pylori. The most promising results come from L. reuteri, which was shown to completely eliminate the infection. A diversity of species and strains may be most effective in treating an H. pylori infection. Lactobacillus rhamnosus GG may help stomach ulcers to heal, but more research is needed in this area.
