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Almutairi R, Basson AR, Wearsh P, Cominelli F, Rodriguez-Palacios A. Validity of food additive maltodextrin as placebo and effects on human gut physiology: systematic review of placebo-controlled clinical trials. Eur J Nutr 2022; 61:2853-2871. [PMID: 35230477 PMCID: PMC9835112 DOI: 10.1007/s00394-022-02802-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 01/06/2022] [Indexed: 01/16/2023]
Abstract
PURPOSE Maltodextrin (MDX) is a polysaccharide food additive commonly used as oral placebo/control to investigate treatments/interventions in humans. The aims of this study were to appraise the MDX effects on human physiology/gut microbiota, and to assess the validity of MDX as a placebo-control. METHODS We performed a systematic review of randomized-placebo-controlled clinical trials (RCTs) where MDX was used as an orally consumed placebo. Data were extracted from study results where effects (physiological/microbial) were attributed (or not) to MDX, and from study participant outcomes data, before-and-after MDX consumption, for post-publication 're-analysis' using paired-data statistics. RESULTS Of two hundred-sixteen studies on 'MDX/microbiome', seventy RCTs (n = 70) were selected for analysis. Supporting concerns regarding the validity of MDX as a placebo, the majority of RCTs (60%, CI 95% = 0.48-0.76; n = 42/70; Fisher-exact p = 0.001, expected < 5/70) reported MDX-induced physiological (38.1%, n = 16/42; p = 0.005), microbial metabolite (19%, n = 8/42; p = 0.013), or microbiome (50%, n = 21/42; p = 0.0001) effects. MDX-induced alterations on gut microbiome included changes in the Firmicutes and/or Bacteroidetes phyla, and Lactobacillus and/or Bifidobacterium species. Effects on various immunological, inflammatory markers, and gut function/permeability were also documented in 25.6% of the studies (n = 10/42). Notably, there was considerable variability in the direction of effects (decrease/increase), MDX dose, form (powder/pill), duration, and disease/populations studied. Overall, only 20% (n = 14/70; p = 0.026) of studies cross-referenced MDX as a justifiable/innocuous placebo, while 2.9% of studies (n = 2/70) acknowledged their data the opposite. CONCLUSION Orally-consumed MDX often (63.9% of RCTs) induces effects on human physiology/gut microbiota. Such effects question the validity of MDX as a placebo-control in human clinical trials.
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Affiliation(s)
- Rawan Almutairi
- Department of Pathology, Case Western Reserve University, 2109 Adelbert Road, Cleveland, OH, 44106, USA
| | - Abigail Raffner Basson
- Department of Medicine and Division of Gastroenterology & Liver Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Digestive Health Research Institute, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Pamela Wearsh
- Department of Pathology, Case Western Reserve University, 2109 Adelbert Road, Cleveland, OH, 44106, USA
| | - Fabio Cominelli
- Department of Medicine and Division of Gastroenterology & Liver Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Digestive Health Research Institute, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
- University Hospitals Research and Education Institute, University Hospital Cleveland Medical Center, Cleveland, OH, USA
| | - Alexander Rodriguez-Palacios
- Department of Medicine and Division of Gastroenterology & Liver Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
- Digestive Health Research Institute, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.
- Germ-Free and Gut Microbiome Core, Cleveland Digestive Diseases Research Core Center, Case Western Reserve University, 2109 Adelbert Road, Cleveland, OH, USA.
- University Hospitals Research and Education Institute, University Hospital Cleveland Medical Center, Cleveland, OH, USA.
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A comprehensive review of functional dyspepsia in pediatrics. Clin J Gastroenterol 2021; 15:30-40. [PMID: 34854065 DOI: 10.1007/s12328-021-01561-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 11/14/2021] [Indexed: 10/19/2022]
Abstract
Functional gastrointestinal disorders have been known as a diagnosis of exclusion since the Rome Foundation first created these criteria in 1990. Since that time, a large amount of research and clinical data has better clarified the mechanisms and treatment options for these. Functional dyspepsia is caused by physiologic, genetic, environmental, and psychological factors, as well as various functional abnormalities, such as increased sensitivity to acid, increased sensitivity to duodenal lipids and low-grade inflammation. This disorder has significant symptom overlap between other functional disorders, such as irritable bowel syndrome and gastroparesis, but has differential criteria and two new subclasses: postprandial distress syndrome and epigastric pain syndrome. Diagnosis of functional dyspepsia should be based upon appropriate clinical evaluation in tandem with Rome IV criteria. In recent years, many treatment measures for functional dyspepsia have been studied, such as pharmacologic intervention, behavioral therapy, or alternative therapy, an example being hypnotherapy. These treatment measures have proven to be effective in symptom reduction in pediatrics. Though this disorder is functional, it has been shown to cause a significant impact on pediatric patients' quality of life continuing into adulthood.
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Jefferson A, Adolphus K. The Effects of Intact Cereal Grain Fibers, Including Wheat Bran on the Gut Microbiota Composition of Healthy Adults: A Systematic Review. Front Nutr 2019; 6:33. [PMID: 30984765 PMCID: PMC6449473 DOI: 10.3389/fnut.2019.00033] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 03/07/2019] [Indexed: 12/14/2022] Open
Abstract
The human microbiota is increasingly recognized as a major factor influencing health and well-being, with potential benefits as diverse as improved immunity, reduced risk of obesity, Type 2 diabetes, and improved cognition and mood. Bacteria inhabiting the gut are dependent on the provision of fermentable dietary substrates making diet a major factor driving the composition of the human gut microbiota. Dietary fiber may modify microbiota abundance, diversity, and metabolism including short-chain fatty acid production. The majority of research to date has explored isolated fibers, and the influence of habitual fiber consumption is less well-established. The aim of the current article was to systematically review evidence from human intervention studies for the effects of intact cereal fibers, and their active sub-fractions, on gut microbiota composition in healthy adults. Studies published in the past 20 years were identified through the PubMed and Cochrane electronic databases. Inclusion criteria were: healthy adult participants (>18 years), inclusion of at least one intact cereal fiber, or its sub-fraction, and measurement of fecal microbiota related outcomes. As every individual has a unique microbiota many trials utilized a cross-over design where individuals acted as their own control. Outcome measures included change to the microbiota, species diversity, or species abundance, or metabolic indicators of microbiota fermentation such as short chain fatty acids or fecal nitrogen. Two hundred and twenty three publications were identified and 40 included in the final review. In discussing the findings, particular attention has been paid to the effects of wheat fiber, bran, and arabinoxylans (AXOS) as this is the dominant source of fiber in many Western countries. Thirty-nine of the forty-two studies demonstrated an increase in microbiota diversity and/or abundance following intact cereal fiber consumption, with effects apparent from 24 h to 52 weeks. Increases in wheat fiber as low as 6–8 g were sufficient to generate significant effects. Study duration ranged from 1 day to 12 weeks, with a single study over 1 year, and exploration of the stability of the microbiota following long-term dietary change is required. Increasing cereal fiber consumption should be encouraged for overall good health and for gut microbiota diversity.
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Shin A, Preidis GA, Shulman R, Kashyap PC. The Gut Microbiome in Adult and Pediatric Functional Gastrointestinal Disorders. Clin Gastroenterol Hepatol 2019; 17:256-274. [PMID: 30153517 PMCID: PMC6314902 DOI: 10.1016/j.cgh.2018.08.054] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 07/23/2018] [Accepted: 08/21/2018] [Indexed: 02/07/2023]
Abstract
The importance of gut microbiota in gastrointestinal (GI) physiology was well described, but our ability to study gut microbial ecosystems in their entirety was limited by culture-based methods prior to the sequencing revolution. The advent of high-throughput sequencing opened new avenues, allowing us to study gut microbial communities as an aggregate, independent of our ability to culture individual microbes. Early studies focused on association of changes in gut microbiota with different disease states, which was necessary to identify a potential role for microbes and generate novel hypotheses. Over the past few years the field has moved beyond associations to better understand the mechanistic implications of the microbiome in the pathophysiology of complex diseases. This movement also has resulted in a shift in our focus toward therapeutic strategies, which rely on better understanding the mediators of gut microbiota-host cross-talk. It is not surprising the gut microbiome has been implicated in the pathogenesis of functional gastrointestinal disorders given its role in modulating physiological processes such as immune development, GI motility and secretion, epithelial barrier integrity, and brain-gut communication. In this review, we focus on the current state of knowledge and future directions in microbiome research as it pertains to functional gastrointestinal disorders. We summarize the factors that help shape the gut microbiome in human beings. We discuss data from animal models and human studies to highlight existing paradigms regarding the mechanisms underlying microbiota-mediated alterations in physiological processes and their relevance in human interventions. While translation of microbiome science is still in its infancy, the outlook is optimistic and we are advancing in the right direction toward precise mechanism-based microbiota therapies.
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Affiliation(s)
- Andrea Shin
- Division of Gastroenterology and Hepatology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Geoffrey A Preidis
- Section of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas
| | - Robert Shulman
- Section of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas
| | - Purna C Kashyap
- Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota.
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Scarpellini E, Deloose E, Vos R, Francois I, Delcour JA, Broekaert WF, Verbeke K, Tack J. The effect of arabinoxylooligosaccharides on upper gastroduodenal motility and hunger ratings in humans. Neurogastroenterol Motil 2018; 30:e13306. [PMID: 29436142 DOI: 10.1111/nmo.13306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 01/09/2018] [Indexed: 02/08/2023]
Abstract
BACKGROUND AND AIMS Prebiotics such as Arabinoxylooligosaccharides (AXOS) are non-digestible, fermentable food ingredients stimulating growth/activity of colonic bacteria with enhanced carbohydrates fermentation (CF) in humans. The migrating motor complex (MMC) of the gastrointestinal tract has been recently identified as an important hunger signal, but no data are available yet on the role of acute CF on MMC activity and related hunger ratings. Thus, we aimed to study the effect of acute AXOS CF on MMC and hunger in humans. METHODS A total of 13 healthy volunteers were randomized in a single-blind crossover placebo-controlled study where 9.4 g of AXOS or 10 g of maltodextrin and 1 g of unlabelled lactose ureide (LU) were given 12 hours prior to the study and, in the next morning, together with a pancake containing 500 mg of 13 C-LU. In 10 hours after the meal, 13 CO2 and hydrogen excretion were determined every 15 minutes while hunger/appetite ratings every 2 minutes through a VAS questionnaire. Five hours after the meal, antroduodenal motility was measured using HRM. KEY RESULTS AXOS significantly increased CF (158 ± 81 vs 840 ± 464 H2 ppm*minute, placebo vs AXOS, P < .05) without affecting the orocecal transit time (OCTT). AXOS had no significant effect on the occurrence, origin, and duration of phase III and on the total number, origin, and duration of phases I and II. Hunger and appetite scores prior and after phase III were not affected by AXOS. CONCLUSIONS AXOS acutely increases colonic fermentation, but this neither affects OCTT, activity of the MMC, nor interdigestive hunger scores in man.
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Affiliation(s)
- E Scarpellini
- Division of Gastroenterology, Department of Internal Medicine, TARGID, University Hospital Gasthuisberg, Leuven, Belgium
| | - E Deloose
- Division of Gastroenterology, Department of Internal Medicine, TARGID, University Hospital Gasthuisberg, Leuven, Belgium
| | - R Vos
- Division of Gastroenterology, Department of Internal Medicine, TARGID, University Hospital Gasthuisberg, Leuven, Belgium
| | - I Francois
- Laboratory of Food Chemistry and Biochemistry & Leuven Food Science and Nutrition Research Centre (LFoRCe), Catholic University of Leuven, Leuven, Belgium
| | - J A Delcour
- FUGEIA NV, Arenberg Science Park, Leuven, Belgium
| | | | - K Verbeke
- Division of Gastroenterology, Department of Internal Medicine, TARGID, University Hospital Gasthuisberg, Leuven, Belgium
| | - J Tack
- Division of Gastroenterology, Department of Internal Medicine, TARGID, University Hospital Gasthuisberg, Leuven, Belgium
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