Inhibitory effect of polyunsaturated fatty acids on the growth of Helicobacter pylori: a possible explanation of the effect of diet on peptic ulceration

Nutrient signaling: evolutionary origins of the immune-modulating effects of dietary fat

Many dietary fatty acids (FA) have potent effects on inflammation, which is not only energetically costly, but also contributes to a range of chronic diseases. This presents an evolutionary paradox: Why should the host initiate a costly and damaging response to commonly encountered nutrients? We propose that the immune system has evolved a capacity to modify expenditure on inflammation to compensate for the effects of dietary FA on gut microorganisms. In a comprehensive literature review, we show that the body preferentially upregulates inflammation in response to saturated FA that promote harmful microbes. In contrast, the host opften reduces inflammation in response to the many unsaturated FA with antimicrobial properties. Our model is supported by contrasts involving shorter-chain FA and omega-3 FA, but with less consistent evidence for trans fats, which are a recent addition to the human diet. Our findings support the idea that the vertebrate immune system has evolved a capacity to detect diet-driven shipfts in the composition of gut microbiota from the profile of FA consumed and to calibrate the costs of inflammation in response to these cues. We conclude by extending the nutrient signaling model to other nutrients, and consider implications for drug discovery and public health.

Docosahexaenoic acid inhibits Helicobacter pylori growth in vitro and mice gastric mucosa colonization

H. pylori drug-resistant strains and non-compliance to therapy are the major causes of H. pylori eradication failure. For some bacterial species it has been demonstrated that fatty acids have a growth inhibitory effect. Our main aim was to assess the ability of docosahexaenoic acid (DHA) to inhibit H. pylori growth both in vitro and in a mouse model. The effectiveness of standard therapy (ST) in combination with DHA on H. pylori eradication and recurrence prevention success was also investigated. The effects of DHA on H. pylori growth were analyzed in an in vitro dose-response study and n in vivo model. We analized the ability of H. pylori to colonize mice gastric mucosa following DHA, ST or a combination of both treatments. Our data demonstrate that DHA decreases H. pylori growth in vitro in a dose-dependent manner. Furthermore, DHA inhibits H. pylori gastric colonization in vivo as well as decreases mouse gastric mucosa inflammation. Addition of DHA to ST was also associated with lower H. pylori infection recurrence in the mouse model. In conclusion, DHA is an inhibitor of H. pylori growth and its ability to colonize mouse stomach. DHA treatment is also associated with a lower recurrence of H. pylori infection in combination with ST. These observations pave the way to consider DHA as an adjunct agent in H. pylori eradication treatment.

Impact of impurities in biodiesel-derived crude glycerol on the fermentation by Clostridium pasteurianum ATCC 6013

During the production of biodiesel, crude glycerol is produced as a byproduct at 10% (w/w). Clostridium pasteurianum has the inherent potential to grow on glycerol and produce 1,3-propanediol and butanol as the major products. Growth and product yields on crude glycerol were reported to be slower and lower, respectively, in comparison to the results obtained from pure glycerol. In this study, we analyzed the effect of each impurity present in the biodiesel-derived crude glycerol on the growth and metabolism of glycerol by C. pasteurianum. The crude glycerol contains methanol, salts (in the form of potassium chloride or sulfate), and fatty acids that were not transesterified. Salt and methanol were found to have no negative effects on the growth and metabolism of the bacteria on glycerol. The fatty acid with a higher degree of unsaturation, linoleic acid, was found to have strong inhibitory effect on the utilization of glycerol by the bacteria. The fatty acid with lower or no degrees of unsaturation such as stearic and oleic acid were found to be less detrimental to substrate utilization. The removal of fatty acids from crude glycerol by acid precipitation resulted in a fermentation behavior that is comparable to the one on pure glycerol. These results show that the fatty acids in the crude glycerol have a negative effect by directly affecting the utilization of glycerol as the carbon source, and hence their removal from crude glycerol is an essential step towards the utilization of crude glycerol.

Conventional and unconventional antimicrobials from fish, marine invertebrates and micro-algae

All eukaryotic organisms, single-celled or multi-cellular, produce a diverse array of natural anti-infective agents that, in addition to conventional antimicrobial peptides, also include proteins and other molecules often not regarded as part of the innate defences. Examples range from histones, fatty acids, and other structural components of cells to pigments and regulatory proteins. These probably represent very ancient defence factors that have been re-used in new ways during evolution. This review discusses the nature, biological role in host protection and potential biotechnological uses of some of these compounds, focusing on those from fish, marine invertebrates and marine micro-algae.

Antibacterial free fatty acids: activities, mechanisms of action and biotechnological potential

Amongst the diverse and potent biological activities of free fatty acids (FFAs) is the ability to kill or inhibit the growth of bacteria. The antibacterial properties of FFAs are used by many organisms to defend against parasitic or pathogenic bacteria. Whilst their antibacterial mode of action is still poorly understood, the prime target of FFA action is the cell membrane, where FFAs disrupt the electron transport chain and oxidative phosphorylation. Besides interfering with cellular energy production, FFA action may also result from the inhibition of enzyme activity, impairment of nutrient uptake, generation of peroxidation and auto-oxidation degradation products or direct lysis of bacterial cells. Their broad spectrum of activity, non-specific mode of action and safety makes them attractive as antibacterial agents for various applications in medicine, agriculture and food preservation, especially where the use of conventional antibiotics is undesirable or prohibited. Moreover, the evolution of inducible FFA-resistant phenotypes is less problematic than with conventional antibiotics. The potential for commercial or biomedical exploitation of antibacterial FFAs, especially for those from natural sources, is discussed.

Steroids mediate resistance to the bactericidal effect of phosphatidylcholines against Helicobacter pylori

Helicobacter pylori assimilates various steroids as membrane lipid components, but it can also survive in the absence of steroids. It thus remains to be clarified as to why the organism relies on steroid physiologically. In this study, we have found that phosphatidylcholine carrying a linoleic acid molecule or arachidonic acid molecule has the potential to kill steroid-free H. pylori. The bactericidal action of phosphatidylcholines against H. pylori was due to the lytic activity of the phosphatidylcholines themselves and not due to the lytic activity of the unsaturated fatty acids or lyso-phosphatidylcholine resulting from the hydrolysis of the phosphatidylcholines. In contrast to the steroid-free H. pylori, the organism that absorbed and glucosylated free cholesterol was unaffected by the bactericidal action of the phosphatidylcholines. Similarly, H. pylori that absorbed estrone without glucosylating it also resisted the bactericidal action of the phosphatidylcholines. The steroids absorbed by H. pylori existed in both the outer and inner membranes, while the glucosyl-steroids produced via the steroid absorption were localized in the outer membrane rather than in the inner membrane. These results indicate that H. pylori absorbs the steroids to reinforce the membrane lipid barrier and thereby expresses resistance to the bacteriolytic action of hydrophobic compounds such as phosphatidylcholine.

Fatty acid composition of subcutaneous adipose tissue and gastric mucosa: is there a relation with gastric ulceration?

Background

Both in vitro and epidemiological studies indicate that dietary polyunsaturated fatty acids may play a protective role against peptic ulcer in humans. Adipose tissue fatty acid composition is thought to reflect dietary fatty acid intake. The aim of the present study is to investigate adipose and gastric mucosa fatty acid levels in relation to gastric ulceration status.

Methods

Fifty two adult outpatients undergoing upper gastrointestinal tract endoscopy participated in the study. Adipose tissue samples were taken from the abdomen and buttock during the endoscopy procedure and samples from gastric tissue were taken from a subsample of 30 subjects. The presence of Helicobacter pylori was determined using the CLO test. Capillary gas chromatography was used for the extraction of 36 and 42 adipose tissue and gastric mucosa lipids respectively.

Results

The monounsaturated fatty acids (MUFAs) C18:1n-12c, C16:1n-5, C16:4n-1 and the polyunsaturated fatty acids (PUFAs) C16:3n-4, C20:3n-3, C20:4n-6, C21:5n-3 and C18:2n-9c,12t of the gastric mucosa were present in higher proportions in ulcer negative patients. These unsaturated fatty acids, however, each contributed less than 1% on average to total fatty acid content. In addition, higher average levels of eicosapentaenoic acid (EPA) C20:5n-3 and docosahexaenoic acid (DHA) C22:6n-3 were detected in abdominal and buttock samples in CLO negative controls, compared to CLO positive controls. Adipose tissue and gastric mucosa n-6 and trans fatty acid levels were positively linearly correlated (r = 0.37 and 0.41 for n-6 and trans fatty acids respectively).

Conclusion

Certain minor MUFAs and PUFAs of the gastric mucosa appear to be present in higher proportions in ulcer negative patients. Overall, the findings provide only weak evidence of an association between the gastric mucosal fatty acids and the presence of gastric ulceration. The higher average levels of EPA and DHA in abdominal and buttock adipose tissue in CLO negative controls could be an indicator that dietary FAs inhibit Helicobacter pylori growth. Larger studies are necessary to provide evidence of a biologically relevant effect.

Fish oil (Eicosapen) is less effective than metronidazole, in combination with pantoprazole and clarithromycin, for Helicobacter pylori eradication

BACKGROUND

In vitro omega-3-fatty acids (Eicosapen) are bacteriostatic to Helicobacter pylori and have a variety of immuno-modulating effects.

AIM

To investigate the efficacy and tolerability of eicosapen (E) as an antibiotic-sparing component of a triple H. pylori eradication regimen in non-ulcer dyspepsia patients in a randomized, double-blind trial.

METHODS

Non-ulcer dyspepsia patients (n=199), with a normal upper endoscopy and a positive (13)C-urea breath test (UBT) were randomly assigned to either pantoprazole, clarithromycin and metronidazole (PCM) or pantoprazole, clarithromycin and eicosapen (PCE) for 7 days. Four weeks after treatment, H. pylori eradication was determined by UBT. Symptoms were followed up to 16 months.

RESULTS

In the intention-to-treat population, PCM eradicated infection in 78% but PCE was successful in only 34% (P < 0.001). Symptomatic improvement occurred in both groups, and was not related to H. pylori eradication.

CONCLUSION

Eicosapen is unlikely to be useful in H. pylori eradication regimens.

Diet and duodenal ulcer

BACKGROUND

Despite the fact that the main cause of duodenal ulcer incidence and recurrence is the Helicobacter pylori bacterium, more than 80% of Helicobacter pylori-infected people never develop an ulcer. Diet may be one of the most important environmental factors contributing to duodenal ulcer.

AIMS

To explore the role of diet in causation, treatment and prevention of duodenal ulcer recurrence.

METHODS

All research papers published in English from 1966 to October 1999 present in Medline, involving human subjects, and having duodenal ulcer as outcome, entered the review.

RESULTS AND CONCLUSIONS

Soluble fibre from fruit and vegetables seem to be protective against duodenal ulcer and refined sugars a risk factor. The role of fibre in the treatment and prevention of recurrence of duodenal ulcer is uncertain, as is that of essential fatty acids. However, none of the epidemiological studies on the relationship between diet and duodenal ulcer disease controlled for Helicobacter pylori.

Effect of polyunsaturated fatty acids on dexamethasone-induced gastric mucosal damage

BACKGROUND

Increased dietary intake of polyunsaturated fatty acids (PUFAs) is known to be associated with a decrease in the incidence of peptic ulcer disease possibly due to increase in the synthesis of prostaglandins. But, it is also likely that conversion of PUFAs to PGs may not always be required for gastric mucosal protection. Present study was designed to study the role of PUFAs in pathobiology of steroid induce gastric damage in rats.

METHODS

Wistar rats were treated with 5 mg/kg bodyweight of dexamethasone to induce gastric mucosal ulcers. Effects of PUFAs was studied by supplementation of Fish oil (rich in n-3 EPA and DHA) and AA rich oil. Famotidine was used as a positive control. Generation of lipid peroxides, nitric oxide and the activity of anti-oxidant enzymes were also studied.

RESULTS

Dexamethasone induced ulceration was associated with changes in the phospholipid fatty acid profile, levels of lipid peroxidation products, nitric oxide and activity of anti-oxidant enzymes. The fatty acid profile showed an increase in LA and a decrease in other PUFAs like GLA, AA, EPA and DHA. When PUFAs were supplemented in the form of Fish oil and AA rich oil or when the animals were treated with H2-blocker, famotidine, there was a decrease in the incidence of ulceration in the animals associated with near normalization of changes in the phospholipid fatty acid profile. The levels of lipid peroxides, nitric oxide, and anti-oxidant activity also reverted to control values.

CONCLUSIONS

Dexamethasone induced gastric ulceration was prevented by PUFAs. This is supported by the results of our earlier study where in it was noted that in patients with DU plasma lipid peroxides, nitric oxide and phospholipid fatty acid pattern and red cell antioxidant activity were altered similar to those seen in dexamethasone treated group of the present study. These abnormalities, similar to the PUFA treated groups of the present study, reverted to normalcy following treatment of the patients with lansoprazole, a proton pump inhibitor. Further, PUFAs are known to inhibit the growth of Helicobacter pylori in vitro. Hence, it is concluded that PUFAs, free radicals, nitric oxide and anti-oxidants play a significant role in the pathobiology of peptic ulcer.

H. pylori in the pathogenesis of duodenal ulcer: interaction between duodenal acid load, bile, and H. pylori

OBJECTIVE

Helicobacter pylori (H. pylori) growth is inhibited by bile yet it can grow in the duodenal bulb and cause ulcer disease. The aim of this study was to test the effect of bile on H. pylori viability and growth and to determine whether acidification of bile reduces its inhibitory activity.

METHODS

Fresh human bile was collected at laparotomy and tested for inhibitory activity of H. pylori using broth dilution assays. Six clinical isolates of H. pylori obtained from patients with duodenal ulcer were used for each experiment. The bile was diluted from 1:3 to 1:192; its inhibitory effect on H. pylori was tested before and after acidification, treatment with cholestyramine, or chloroform. Bile was acidified to a pH of 2-6, centrifuged at 8000 rpm for 20 min to remove precipitated bile acids, and the supernatant pH readjusted. Controls included BHI broth without bile (positive control) and bile that was acidified to pH 2 and neutralized without centrifugation.

RESULTS

Human bile inhibited H. pylori growth in a dose dependent manner. Growth of all strains was supported for all strains only at a dilution of 1:192. In contrast, after acidification to pH < or =5 and centrifugation to remove precipitated bile acids, all strains grew at a bile dilution of 1:12. Neither chloroform extraction of lipids, nor acidification without centrifugation removed the inhibitory action of bile. In contrast, cholestyramine sequestration of bile acids completely removed all inhibitory activity.

CONCLUSIONS

The duodenal acid load may be the critical factor to explain the ability of H. pylori to colonize the duodenal bulb by precipitating glycine-conjugated bile salts. The combination of a high duodenal acid load and H. pylori infection is likely the critical event in the pathogenesis of H. pylori-related duodenal ulcer disease.

Effects of three different fish oil formulations on Helicobacter pylori growth and viability: in vitro study

Helicobacter pylori infection is currently treated with antimicrobial agents in combination with antacids. Recent studies have described the in vitro bactericidal activity of fish oils and polyunsaturated fatty acids on H. pylori, and reduced rates of duodenal ulcer in people with high intake of these substances. In this study we have tested the in vitro activity of three different fish oil formulations on H. pylori strains using the Kirby Bauer method and an in vitro antibacterial test on bacteria adhered to cellular monolayers. Our results demonstrate that one of the oils is active. In this study we cannot speculate on which component of the active oil is effective and its mechanism of action, but we hypothesize that a higher concentration of icosapentaenoic acid and docosahexaenoic acid occurs in the active oil. Further in vitro and in vivo studies are needed before proposing fish oils as treatment of H. pylori infection.

Helicobacter Pylori

All infected patients with a peptic ulcer should be treated for H. pylori. The role of treating H. pylori in patients with undiagnosed dyspepsia or non-ulcer dyspepsia, those taking nonsteroidal anti-inflammatory medications, or with a family history of gastric cancer remains controversial. Triple therapies consisting of a proton pump inhibitor or ranitidine bismuth citrate and two antibiotics are the current standard of therapy for H. pylori. In general, dual therapies should no longer be used to treat H. pylori. Bismuth triple therapy consisting of bismuth, tetracycline, and metronidazole is a less expensive alternative to proton pump inhibitor-or ranitidine bismuth citrate-based triple therapies. However, bismuth triple therapy is hampered by frequent side effects and the need for qid dosing. In Europe, a 7-day course of therapy appears to be adequate. In the United States, 10-14 days of therapy are currently recommended. Metronidazole resistance in H. pylori strains varies geographically, and negatively influences the effectiveness of therapies containing this antibiotic. Clarithromycin resistance is relatively infrequent at the current time but may be rising in countries where this antibiotic is in use. If a patient remains infected after a course of therapy for H. pylori, the second treatment should avoid the antibiotics used initially.

Oxidant stress, anti-oxidants, nitric oxide and essential fatty acids in peptic ulcer disease

In patients with duodenal ulcer (DU), the plasma levels of nitrite and lipid peroxides, the anti-oxidant content of red cells and plasma phospholipid fatty acid analysis were performed both before and after healing of the ulcer following treatment with lansoprazole, a proton pump inhibitor. These results showed that during the phase of active DU, the concentrations of antioxidants (superoxide dismutase, SOD, catalase and glutathione peroxidase) in red cells were low where as those of lipid peroxides and nitric oxide were high. Of the fatty acids measured, the concentration of palmitic acid (16:0) was increased during the active ulcer phase whereas those of arachidonic acid, alpha-linolenic acid and docosahexaenoic acid were low. These biochemical abnormalities reverted to normal following healing of the ulcer with lansoprazole. These results coupled with the observation that polyunsaturated fatty acids (PUFAs) can inhibit the growth of Helicobacterpylori and heal the ulcer suggest that free radicals, anti-oxidants, nitric oxide and PUFAs may play a significant role in the pathogenesis of DU. If this is true, it suggests that PUFAs can be exploited as potential anti-peptic ulcer drugs.

Dietary factors influence the recovery rates of Helicobacter pylori in a BALB/cA mouse model

The aim of this study was to assess the ability of different mouse diets to sustain an H. pylori infection in BALB/cA mice. Four commercially available mouse diets were compared. Experiment 1: Mice were fed the four diets for seven days before infection, infected three times at two-day intervals with 0.1 ml of 10(9) colony-forming units/ml H. pylori cells. H. pylori strains (n = 4) were cultured on GAB-Camp agar for 2 days, harvested and suspended in PBS. All animals were sacrificed at 2 and 4 weeks post inoculation. Experiment 2: Mice infected for 8 weeks were fed RM2, changed to the different diets for 10 days and sacrificed. Stomachs were collected, cultured on GAB-Camp agar to estimate H. pylori growth and stomach biopsies were analyzed by PCR. There were significant differences between diets in their ability to sustain growth of H. pylori. The range was from a few hundred colonies to no growth at all on the GAB-Camp agar. PCR signals showed good correlation with the culture results. All H. pylori-infected mice gave a significantly higher inflammation score compared to non-infected mice. The diet RM2, having the highest number of culturable H. pylori in the mouse stomach, also showed the highest inflammation. These results suggest that the dietary factors affect the amounts of H. pylori in an infection of BALB/cA mice.

Hypothesis: cis-unsaturated fatty acids as potential anti-peptic ulcer drugs

It is now reasonably well established that Helicobacter pylori is the most likely cause for duodenal ulcer. What is not clear is how this infection is related to the excess acid production, why few people with Helicobacter pylori infection have duodenal ulcer and how diet is related to duodenal ulcer. Here it is suggested that a deficiency of cis-unsaturated fatty acids (otherwise called as polyunsaturated fatty acids, PUFAs) especially gamma-linolenic acid, dihomo-gamma-linolenic acid, arachidonic acid and eicosapentaenoic acid may be responsible for duodenal ulcer. Patients with active duodenal ulcer are known to have low concentrations of these PUFAs in their plasma phospholipid fraction and they revert to normal levels after treatment with H2 blockers. In addition, these PUFAs have the ability to inhibit the growth of Helicobacter pylori, suppress acid production and both in experimental animals and humans these PUFAs could heal the ulcer and protect the gastric mucosa from aspirin and steroid-induced damage. Further, PUFAs have other beneficial actions such as capacity to prevent/arrest atherosclerosis, lower plasma cholesterol and triglyceride levels and cytotoxic action on tumour cells. Since PUFAs can be administered over long periods of time and are relatively non-toxic, it is suggested that PUFAs may be exploited as potential anti-ulcer agents.

Clarification of the link between polyunsaturated fatty acids and Helicobacter pylori-associated duodenal ulcer disease: a dietary intervention study

Epidemiological evidence has suggested that the declining prevalence of duodenal ulcer disease may be attributable to rising consumption of polyunsaturated fatty acids, a hypothesis supported by in vitro evidence of toxicity of such substances to Helicobacter pylori. The objective of the present study was to establish whether this association is causal. Forty patients with proven infection with H. pylori and endoscopic evidence of past or present duodenal ulcer disease were randomized to receive either polyunsaturated fatty acids (PUFA group), in the form of capsules and margarine, or a placebo (control). Both groups received concurrent H2 antagonist therapy. Efficacy of therapy was determined endoscopically by assessment of ulcer healing while H. pylori status was determined by antral biopsy, urease (EC 3.5.1.5) culture and histological assessment of the severity of H. pylori infection. Antral levels of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) were quantified. Compliance was monitored. Before treatment, both groups were comparable for severity of H. pylori infection, smoking status and levels of LTB4 and PGE2. Despite a significant difference in consumption of linoleic acid (19.9 (SE 1.6) g for PUFA group v. 6.7 (SE 0.8) g for controls (P < 0.01) and linolenic acid (2.6 (SE 0.2) g v. 0.6 (SE 0.03) g (P < 0.01) there was no significant change in either the severity of H. pylori infection or prostaglandin levels in either group at 6 weeks. Consumption of a considerable amount of PUFA does not inhibit the colonization of the stomach by H. pylori nor does this alter the inflammatory changes characteristic of H. pylori gastritis. We conclude that the association between duodenal ulceration and a low level of dietary PUFA is likely to be spurious, probably reflecting the effect of confounding factors such as affluence, social class or smoking.

Capsaicin as an inhibitor of the growth of the gastric pathogen Helicobacter pylori

Capsaicin, the active ingredient in chili, has been implicated as both a cytoprotective and a detrimental agent to the gastric mucosa. The effect of capsaicin on Helicobacter pylori has not been investigated previously. Therefore, we performed in vitro time- and concentration-dependent studies to examine the growth of H. pylori in the presence of capsaicin. Capsaicin specifically inhibited growth of H. pylori dose-dependently at concentrations greater than 10 micrograms ml-1 (P < 0.05) but did not inhibit the growth of a human fecal commensal Escherichia coli strain. Bactericidal activity was observed within 4 h. Capsaicin continued to exhibit bactericidal activity when incubated at pH values as low as 5.4. Ingestion of chili, therefore, could have a protective effect against H. pylori-associated gastroduodenal disease. This effect deserves further study in animal models.

Susceptibility of Helicobacter pylori to bactericidal properties of medium-chain monoglycerides and free fatty acids

Previous studies have shown that various short- and medium-chain free fatty acids (FFAs) and their corresponding monoacylglycerol esters (MGs) have antibacterial activity in vitro against primarily gram-positive bacteria. More recent studies have also shown that the growth of Helicobacter spp. is inhibited by linoleic acid and arachidonic acid. The purpose of the present study was to evaluate the susceptibility of Helicobacter pylori to the in vitro bactericidal properties of medium-chain MGs and FFAs. Incubation of H. pylori with saturated MGs, ranging in carbon chain length from C10:0 to C14:0, at 1 mM caused a 4-log-unit or greater reduction in the number of viable bacteria after exposure for 1 h. Lower levels of bactericidal activity were observed with C9:0, C15:0, and C16:0 MGs. In contrast, lauric acid (C12:0) was the only medium-chain saturated FFA with bactericidal activity against H. pylori. The MGs and FFAs were bactericidal after incubation for as little as 15 min at neutral or acidic pHs. Higher levels of MGs and FFAs were required for bactericidal activity in the presence of higher amounts of protein in liquid diets. We also found that the frequency of spontaneous development of resistance by H. pylori was higher for metronidazole and tetracycline (10(-5) to 10(-6)) than for C10:0 MG, C12:0 MG, and C12:0 FFA (< 10(-8)). Collectively, our data demonstrate that H. pylori is rapidly inactivated by medium-chain MGs and lauric acid and exhibits a relatively low frequency of spontaneous development of resistance to the bactericidal activity of MGs. Further studies are needed to establish whether MGs may be useful either alone or with other known therapeutic agents in the management of H. pylori infections in humans.

Cyclodextrins for growth of Helicobacter pylori and production of vacuolating cytotoxin

Growth of Helicobacter pylori in liquid culture requires the addition of media supplements that often interfere with subsequent purification of bacterial antigens. In order to determine whether cyclodextrins can substitute for conventional H. pylori growth supplements, we cultured H. pylori in the presence of five commercially available cyclodextrins. The effect of these compounds on the production of the vacuolating cytotoxin antigen was evaluated. Several cyclodextrins supported flourishing growth and permitted the consistent production of vacuolating cytotoxin. These data suggest that Brucella broth supplemented with cyclodextrins is an improved medium for bacterial culture and industrial production of H. pylori antigens.