Gut microbiota is a hot and fast‐moving topic, and paediatricians need to monitor the latest developments

In this issue of Acta Paediatrica, Goulet et al1 summarise current knowledge on early events that could affect the development of the gut microbiota. The paper, on behalf of the European Paediatric Association, states that paediatricians play a key role in preventing early harmful events that could permanently influence the development of the gut microbiota in childhood. Indeed, growing evidence suggests that early gut microbiota colonisation plays an important role in health and disease and that is why paediatricians are so important. Alterations in the gut microbiota, known as dysbiosis, may be caused by a number of factors during childhood, including mode of delivery, type of feeding and drugs, such as antibiotics and proton pump inhibitors. As dysbiosis has been associated with a variety of diseases, including allergies, obesity, irritable bowel syndrome, necrotising enterocolitis, type 1 diabetes and autism, knowledge of these aetiological factors is important for everyone who takes care of children, including paediatricians. The current focus with regard to the gut microbiota is mainly on bacteria. However, fungi and viruses also influence the gut microbiota, although data on their relationship with dysbiosis are limited.2, 3 Furthermore, the exact gut microbiota changes in patients with specific diseases remain a matter of debate. Goulet et al noted that it is almost impossible to delineate the causes from the consequences, as few studies have shown that changes in the gut microbiota precede inflammation. Thus, while it is tempting to think that analyses of the gut microbiota can help to predict or diagnose diseases, we are not there yet. Interest in this subject is linked to interventions that target the gut microbiota, which could potentially benefit health and reduce the risk of diseases. Once again, there is a role for paediatricians in the wise administration of such interventions and only those with documented efficacy and safety should be used. Goulet et al's paper summarises the indications for using specific probiotics, but not probiotics in general.1 This is in line with the current view that the health effects of probiotics seem to be strain specific. It is worth noting that the authors searched the literature up until June 2018 and a number of reports have been published after that date that questioned the efficacy and safety of probiotics. Two studies based on animal and human experiments4, 5 suggested that probiotic administration, at least the combination of 11 strains used by the investigators, did not consistently change the gut microbiota composition. The results of these studies also indicated that individual responses to probiotic administration differ and that probiotic administration may have adverse effects after antibiotic therapy. Additionally, evidence from a large randomised controlled trial negated the previously reported efficacy of Lactobacillus rhamnosus GG for treating acute gastroenteritis in children.6 Similar results were reported in another randomised controlled trial performed in Canada, which showed that probiotics had no effects in children who received a probiotic product that contained a combination of Lactobacillus rhamnosus R0011 and Lactobacillus helveticus R0052 or received a placebo.7 The combined findings of these studies indicate that we still need a better understanding of probiotics. There is much less evidence on the efficacy and safety of prebiotics than probiotics, and Goulet et al1 did not summarise the indications for their use. However, the concept of prebiotic administration is very attractive, particularly when there are concerns with regard to the administration of live microorganisms (probiotics), with the potential risk of infection or transfer of antibiotic resistance genes. There are ongoing discussions about the term synbiotic. In principle, this term, as defined by Goulet et al,1 refers to a product that includes both a probiotic and a prebiotic. Goulet et al describe how synbiotics may act, for example by improving the viability of probiotic microorganisms and increasing levels of substances such as short-chain fatty acids and ketones. The authors also provide a table that summarises the potential beneficial activity of synbiotics in different clinical conditions. However, we currently lack precise details on synbiotics, such as what criteria they should fulfil and what level of evidence is needed. This has prompted the International Scientific Association of Probiotics and Prebiotics (ISAPP) to convene a panel to develop a consensus definition of synbiotics to facilitate further discussion on this topic. There is even less agreement about the definitions of the terms postbiotics and paraprobiotics. Although Goulet et al define and describe the actions of these products,1 these definitions are likely to be modified in the future. The ISAPP has started working on this as well. The attractiveness of these interventions, particularly when compared with probiotics, is that they avoid the risks of administering live microorganisms such as infections, the transfer of antibiotic resistance genes and potential inflammatory responses. These risks may limit the use of probiotics in vulnerable populations, such as preterm infants or immunocompromised subjects. Although Goulet et al focus on postbiotics and paraprobiotics, a much longer list of terms related to interventions targeting the gut microbiota can be found in the literature. In addition to probiotics, prebiotics and synbiotics, terms such as pharmabiotics, paraprobiotics, ghost probiotics, postbiotics, probioceuticals, probiotaceuticals, biogenics, oncobiotics, psychobiotics and many others are used.8 However, the evidence behind the use of many of them in a therapeutic setting is often lacking. Two aspects that were only briefly addressed by Goulet et al include the safety and quality of interventions targeting the gut microbiota.1 Overall, interventions are considered safe for use in otherwise healthy populations. However, a 2018 systematic review found that about a third of the 384 trials it evaluated did not provide information on harm and only 2% adequately reported key safety components.9 Thus, uncertainty remains due to the lack of and, or, inadequate reporting of harmful effects. There is also concern with regard to the quality of products targeting the microbiota and about probiotics in particular.10 It is clear that gut microbiota research is a hot topic. In fact, it is booming. However, what is true today may not be true tomorrow. As paediatricians, we need to keep up-to-date with the latest research, as our actions in administering products that target the gut microbiota may have long-term positive or negative effects. This emphasises the important link between paediatricians and the health of our patients’ gut microbiota. The author has no conflicts of interest to declare.

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.