A letter of reply to: Can the gastrointestinal microbiota be modulated by dietary fibre to treat obesity? Davis, H.C. Ir J Med Sci (2017). https://doi.org/10.1007/s11845-017-1686-9 LETTER TO THE EDITOR A letter of reply to: Can the gastrointestinal microbiota be modulated by dietary fibre to treat obesity? Davis, H.C. Ir J Med Sci (2017). https://doi.org/10.1007/s11845-017-1686-9 Paul MacDaragh Ryan1 Received: 24 January 2018 /Accepted: 8 February 2018 /Published online: 21 February 2018 # Royal Academy of Medicine in Ireland 2018 Dear Sir or Madam, I write to agree with Davis’ assessment of the role which our fibre intake and gut microbiome may play in triggering, exacerbating or managing obesity. However, I also wish to levy a caveat to this concept. In Ireland, we find ourselves acutely aware of rising obesity rates [1]. While health research has spent much of the previous decades conducting a form of nutritional ‘witch-hunt’ for the culpable micro or macronutrient (i.e. dietary fats, refined car- bohydrates, artificial sweeteners), we may indeed have overlooked something fundamental which was largely lost from our diet. In both time and space, dietary fibre appears to associate neatly with metabolic function. Current estimates of Irish adult dietary fibre intake lie at a paltry ~ 19 g day−1 [2], substantially short of the current RDA of 25 g day−1, which itself seems alarmingly inadequate when considering that of ancient and non-‘Westernised’ popula- tions. Perhaps even more concerning is the fact that our met- abolically impressionable paediatric population consumes roughly half this amount of fibre. In line with this, there is now convincing preclinical evi- dence which suggests that consecutive generations of low- fibre intake compound microbiome diversity degeneration [3]. That is to say that we lose microbial species, and with them their metabolic benefits, with each generation sustained by our low-fibre Westernised diet. We must, therefore, make a conscious and concerted effort as a national and global community to abridge the dietary fibre gap, if we are to improve the metabolic health prospects of generations to come. Kind Regards, Paul MacDaragh Ryan BSc PhD Graduate Entry Medical Student, University College Cork Compliance with ethical standards Conflict of interest The author declares that he has no conflict of interests References 1. Abarca-Gómez L, Abdeen ZA, Hamid ZA, Abu-Rmeileh NM, Acosta-Cazares B, Acuin C, Adams RJ, Aekplakorn W, Afsana K, Aguilar-Salinas CA, Agyemang C (2017) Worldwide trends in body- mass index, underweight, overweight, and obesity from 1975 to 2016: a pooled analysis of 2416 population-based measurement studies in 128·9 million children, adolescents, and adults. Lancet 390(10113):2627–2642 2. Flynn A., Walton J., Gibney M., Nugent A., B McNulty (2011) National Adult Nutrition Survey. Irish Universities Nutrition Alliance (IUNA) 3. Sonnenburg ED, Smits SA, Tikhonov M, Higginbottom SK, Wingreen NS, Sonnenburg JL (2016) Diet-induced extinctions in the gut microbiota compound over generations. Nature 529(7585): 212–215. https://doi.org/10.1038/nature16504 http://www.nature. com/nature/journal/v529/n7585/abs/nature16504.html- supplementary-information * Paul MacDaragh Ryan paul_ryan@umail.ucc.ie 1 School of Medicine, University College Cork, Cork, Ireland Irish Journal of Medical Science (1971 -) (2018) 187:537 https://doi.org/10.1007/s11845-018-1768-3 http://crossmark.crossref.org/dialog/?doi=10.1007/s11845-018-1768-3&domain=pdf https://doi.org/10.1038/nature16504 http://www.nature.com/nature/journal/v529/n7585/abs/nature16504.html-supplementary-information http://www.nature.com/nature/journal/v529/n7585/abs/nature16504.html-supplementary-information http://www.nature.com/nature/journal/v529/n7585/abs/nature16504.html-supplementary-information mailto:paul_ryan@umail.ucc.ie A... References