In this interview, Andrea Doolan, CEO and co-founder of Atlantia Clinical Trials, describes a case study trial on integrating video capsule endoscopy technology within probiotic research. Andrea describes the link between non-steroidal anti-inflammatory drugs and microbiota changes in subjects and how significant an impact this has before exploring the detail of the clinical trial itself.
The object of the clinical trial was to investigate the ability of the probiotic strain to attenuate and or reverse low-dose long-term NSAIDs induced deterioration of small intestinal mucosa tissue, as assessed by video capsule endoscopy in healthy volunteers. The findings were then assessed, with a number of conclusions drawn for the future of the field.
Please provide an outline of how non-steroidal anti-inflammatory drugs are linked to microbiota changes.
Non-steroidal anti-inflammatory drugs, also known as NSAIDs, are commonly used worldwide, both as prescription-only medicines and as over-the-counter preparations. However, a low dose of NSAIDs is associated with gastrointestinal injury. Live bacteria, formulated as probiotics, may offer a safe alternative to prevent or at least decrease the negative side effects of NSAIDs, such as aspirin. Given such deleterious composition changes to the microbiota, in addition to direct effects on mucus and endothelial tissue, this may increase the risk of NSAIDs in arthropathy.
The sponsor of the present clinical trial hypothesized that an intervention targeting microbiome host interactions might offer an attractive preventative strategy. The present clinical trial was the first in a clinical development program aiming to bring a product containing a selected strain to market, which was able to attenuate and or reverse NSAID-induced small intestinal damage, and GI symptoms and NSAIDs users.
The sponsored strain selection was based on the anti-inflammatory properties of certain bifidobacteria and experimental preclinical evidence for a role of bifidobacteria in NSAIDs-associated observation, as well as on unpublished preclinical screening data. The trial outlined the development of a clinical model to assess the quantitative and time-resolved induction of small intestinal injury upon ASA administration. Probiotic bacteria have demonstrated the possible therapeutic effects against intestinal inflammation and the sponsor, a world-class innovative company, was focused on bringing a treatment to market.
They have previously performed several in vitro screening assays in order to characterize approximately 200 different strains. Five strains were then selected based on their characteristics in-vitro. The selected five strains were then tested in a wrap model of colitis before the selection of a strain for this study. The sponsor needed a highly experienced research partner able to assess the deterioration of small intestinal mucosa tissue. However, they needed a less-invasive method in order to overcome the ethical burdens.
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What were the main objectives of the clinical trial?
The main objectives were to investigate the ability of the probiotic strain to attenuate and or reverse low-dose, long-term NSAID-induced deterioration of small intestinal mucosa tissue, as assessed by video capsule endoscopy in healthy volunteers.
Furthermore, an additional objective was to investigate the ability of the probiotic strain to attenuate and or reverse low-dose long-term NSAID-induced GI symptoms, as assessed by area under the curve ulcer numbers and by AUC of pain symptoms score for the gastrointestinal symptom rating scale. It was also important to investigate co-administration of the probiotic strain to-low dose, long-term NSAIDs on changes in multiple biomarkers of general intestinal barrier function in blood and fecal samples.
Additionally, a clinical challenge model was established to investigate the probiotic strain’s ability to attenuate and/or reverse deterioration in the healthy human gastrointestinal tract.
What is capsule endoscopy, and how was it used here?
The deterioration was induced by a chemical agent commonly used, which had well-established deteriorating effects on the small intestine. For the primary endpoint, we used the capsule endoscopy test that assessed the small intestinal damage. Capsule endoscopy has been reviewed in a technology status evaluation report by the American society of gastrointestinal endoscopy and is now the gold standard for assessing gastrointestinal bleeding – and indications for its use are continuing to expand. Current uses include exploration and surveillance of bowel pathology, such as Crohn’s Disease, polyps, small bowel malignancy and drug-induced mucosal injury.
Capsule endoscopy is generally a safe and well-tolerated procedure. Atlantia has a highly expert team on managing these technologies when conducting trials, and was a perfect fit for the sponsor. The trial was a single-site, randomized, double-blind, placebo-controlled, two-armed, parallel-group trial in healthy adult volunteers. It investigated the effect of daily probiotic strain or placebo intake when co-administered with a daily intake of 300mg of aspirin. The trial was conducted in accordance with the ethical principles set forth in the current version of the Declaration of Helsinki and the International Conference on Harmonization Good Clinical Practice.
What was the duration and design of the trial, and what were the requirements of the subjects?
The trial included a run-in period of two weeks, followed by a six-week intervention period, where the probiotic or placebo and NSAIDs were co-administered. After the six weeks, the probiotic placebo was given for an additional two weeks to investigate the potential effect of the probiotic on intestinal healing after long-term NSAIDs use. Subjects participated in the trial for a total duration of 10 weeks, including the run-in phase.
Throughout the entire trial, subjects were instructed to maintain their habitual lifestyle with regard to diet, physical activity and sleep habits. Intake of probiotic products, as well as food and food supplements containing probiotics, were not allowed from the screening visit for the study duration. Small intestinal mucosa deterioration was evaluated using video capsule endoscopy, as well as indirect biomarkers in feces and blood samples.
Subjects also filled out the GS or S gastrointestinal symptom rating scale questionnaire, which assesses GI symptoms and pain. Each subject underwent six video capsule endoscopies over the course of the eight-week intervention. Capsule endoscopy is deemed to be a relevant and acceptable method to evaluate both mild and severe intestinal damage caused by a low dose of aspirin, measured as the area under the curve.
Between July and October 2017, 109 subjects were screened for eligibility, of whom 75 were enrolled and randomized. Among 75 randomized subjects, nine subjects were discontinued during the intervention, and therefore efficacy data was obtained in a total of 66 subjects; 35 in the active arm and 31 in the placebo arm. The arms were, in general, similar in their baseline parameters, including gender distribution, age, BMI and blood pressure. Accountability of both ASA and trial products was, in general, very high in both arms.
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What were the significant findings of the trial?
This clinical trial met its primary endpoint with a statistically significant lower AUC lower score, as captured by VCE during the eight weeks’ intervention, in the Bif195 arm, versus the placebo.
In addition, the trial met its secondary endpoint with a significantly lower AUC ulcer number, as also captured by VCE during the intervention. The other secondary endpoints did not meet statistical significance, with the exception of fecal calprotectin, which was significantly lower in the treatment arm compared to the placebo arm.
ASA and trial product were both generally well-tolerated by the subjects. In total, 32 adverse events were registered from 22 different subjects, included in the safety analysis data set. Twelve of these adverse events were reported from the Bif195 arm and 20 from the placebo arm. None of the adverse events were related to the Bif intake, while in total, 10 of them were assumed related to ASA intake, as assessed by the principal investigator. The number of adverse events related to ASA did not differ between the two intervention arms.
DNA sequencing of all fecal samples obtained showed an increase after randomization in bifidobacterium breve in fecal samples obtained from subjects in the Bif195 arm, compared to the placebo arm confirming trial product compliance.
The Bif195 intervention was not associated with significant changes in the abundance of specific microbial taxa, nor in the changes in the overall microbiome composition. Serum PGE2 and TXB2 concentrations showed a robust decline during ASA intake and reversed to baseline levels during the final two weeks’ recovery period. The Bif195 intervention did not have significant effects on these data sets.
What could be concluded from these findings?
The trial results indicate that Bif195 confers significant and objectively verifiable protection against small intestinal damage caused by a six-week ASA challenge in healthy volunteers. The efficacy of Bif195 and NSAIDs associated with small intestinal injury may be partly explained by the difference in pathogenesis between NSAIDs associated with small intestinal injury, and NSAIDs associated with gastropathy, whereas acid and pepsin are the principal luminal aggressors in NSAIDs gastropathy. Bile and bacteria are the luminal factors in NSAID arthropathy.
Although preclinical studies in experimental animals have been encouraging, previous trials in humans of punitive probiotics in NSAID arthropathy have been inconsistent. Certain strains of bifidobacteria are known to strengthen the intestinal epithelial layer and modulate the local immuno-inflammatory response, as well as compete with potential bacteria aggressors.
The molecular details of bifidobacterial mediated protection against small intestinal epithelial injury are currently under investigation, but one candidate includes the pilus associated protein, tadE, which exerts a proliferative effect on host colonic epithelial following oral consumption of bifidobacterium breve.
This appears to be a characteristic of all bifidobacterium breve and supports the choice of strain used in this trial. The trial's primary and first secondary efficacy criteria were met, thereby highlighting the potential of Bif195 co-treatment in future prevention strategies for a growing population experiencing silent or overt small intestinal arthropathy from chronic ASA use.
Although prior studies have described gastric damage from NSAIDs, we believe that this is the first trial to record the detailed time-resolved kinetics of ASA-induced and reversal of small intestinal damage.
This data set shows a gradual increase in damage observed by VCE during the six weeks of daily ASA intake and a partial reversal towards baseline levels over a two-week recovery period. Furthermore, the small intestinal tactile stratification clearly shows that ASA-induced arthropathy is mainly a localized phenomenon. This site coincides with the localization of the main effect of the Bif195 intervention on ulceration, further highlighting the potential for protective intervention with this strain.
What impact does this trial have on the wider field?
The strategy of performing serial capsule endoscopies in this trial enabled us to obtain the sensitivity needed to observe a significant effect in a dynamic environment where damage formation and healing coexist. Thus, it represents a superior and more sensitive form of assessment than the more usual adopted before or after intervention trial design.
Interestingly, fecal microbiome analysis revealed that changes were limited to a marked increase in the total B breve population in the Bif195 arm. This data provided further evidence that in terms of microbial intervention strategies, targeting the microbiome can be clinically efficacious without inducing major alterations in the overall microbial population structure. Our six-week ASA challenge model yielded minor responses in the GSRS questionnaire and in the biomarkers of damage, including IFFA in blood and calprotectin in blood and feces.
Close monitoring of adverse events during this trial suggested that daily oral intake of Bif195 is safe and without side effects. Further clinical trials are required to test whether the strain has clinical significance in other settings and populations, such as chronic users of ASA.
Although encouraging, the present clinical trial has limitations in terms of translation to a real-life clinical setting. The relatively short-term challenge in healthy volunteers for proof of concept relies upon a higher dose of ASA than is most commonly prescribed for primary CVD prevention. However, the dose used is readily available for over-the-counter usage.
It is also noteworthy that a recent report suggested that the current cardioprotective dose of ASA may be insufficient and recommended doses based on a milligrams-per-kilogram basis. Due to our AUC approach and a curve fitted to data points obtained from six different visits, data imputation is not feasible for dropout subjects, where only baseline data is available. Therefore, we must acknowledge that long-term intervention clinical trials will be needed to confirm if Bif195 has long-term clinical efficacy in a larger intention to treat a population of chronic users of ASA, taking lower doses for CVD prevention.
About Atlantia Clinical Trials
Atlantia Clinical Trials Ltd is a CRO that specializes in conducting studies on foods, beverages, and supplements for companies worldwide that want to scientifically validate their functional ingredients to support an: EFSA (European Food Safety Authority) Health Claim; FDA (Food & Drug Administration) Structure Function Claim; or General Product Marketing Claim.
Atlantia works with world-leading scientists (among the top cited 1% internationally, in the areas of digestive health and functional foods) at the: APC Microbiome Institute in University College Cork, Ireland; Teagasc, Moorepark, Ireland, and recognized centers of excellence globally.
Atlantia runs and operates its own clinic sites and conducts all studies to ICH-GCP standard (International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use - Good Clinical Practice). Its team includes physician experts in digestive health, mental health (psychological stress and cognition), cardiovascular health, sports performance, metabolic disease, bone health, immune health, and healthy ageing. The clinical team also includes project managers, research nurses, nutritionists, certified sports trainers and lab researchers.
Atlantia manages all elements from protocol design, placebo manufacture, recruitment, and study execution, to sample and data analysis, statistics, and report/dossier preparation to provide a service that is technically, scientifically, and clinically superior.
The clinical studies cover a broad spectrum of functional food and beverage categories, such as dairy, cereal, probiotics, different protein forms, infant-specific foods, vitamins/minerals, plant or marine extracts, and medical foods.
Randomized clinical food trials: Best clinical practice, quality management & data processing