TABLE 5.

Major conclusions and future research points

Category	Discussion
Major conclusions	Otitis media (OM) is a leading cause of antibiotic prescription in childhood, yet antibiotic use should be limited as much as possible
	The main bacterial pathogens contributing to OM are S. pneumoniae, H. influenzae, and M. catarrhalis, but microbiome studies of OM also suggest a pathogenic role for other taxa, such as Turicella and Alloiococcus
	Microbiome studies in healthy children indicate a protective role against OM for lactic acid bacteria, such as Dolosigranulum, Lactobacillus, and Lactococcus
	Microbiome studies give information about the relative abundances of potential pathogens or protective bacteria, but other criteria need to be considered as well, such as those described in (translated probiotic) Koch’s postulates
	Both clinical studies and molecular mechanisms suggest that probiotics have potential to reduce OM episodes and the related antibiotic use
Future research points	Microbiome information at the strain level could give more information on strain-specific virulence or protection capacities of specific bacteria
	Molecular mechanistic studies on the potential of probiotics against OM pathogens and their adaptation to the targeted niches are necessary to select for the most optimal probiotics
	Clinical studies in humans will further substantiate the therapeutic effectiveness of such selected probiotics and their influence on the local microbiome