Clinical Research Directory

Predictive Value of Hydrogen/Methane Lactose Breath Testing on the Therapeutic Effect of Lactose-free Diet in Moderate to Severe ROME IV IBS.

Lactose intolerance (LI) results from lactose malabsorption (LM) secondary to insufficient hydrolysis of the disaccharide lactose into galactose and glucose (Misselwitz 2019). The undigested lactose will eventually reach the colon, resulting in fermentation from colonic bacteria with production of different compounds such as short chain fatty acids, carbon dioxide, H2 and methane (Catanzaro 2021). These compounds have an osmotic effect and can stimulate colonic contractions. These pathophysiological mechanisms encountered in patients suffering from LI generate symptoms, such as abdominal pain and cramps, flatulence, diarrhea, borborygmi among others. As dairy products are highly present in our Western diet, LI will often be considered in patients presenting with these symptoms and they will be referred for further testing. When LM is diagnosed, a lactose-free diet (LFD) will be advocated to alleviate symptoms. However, studies indicate that individuals with LM should tolerate up to 12 g of lactose when administered in a single dose (Suchy 2010). Irritable bowel syndrome (IBS) is another frequently encountered disorder. According to the Rome IV criteria, it is characterized by abdominal pain associated with a change in stool frequency or consistency, or with symptomatic improvement by defecation (Mearin 2016). Associated symptoms, such as bloating and flatulence, are frequently reported. As such, discerning between IBS and LI based on symptoms alone can be challenging. Moreover lactose is considered part of the so-called fermentable oligo-, di-, monosaccharides and polyols (FODMAPs). A low FODMAP diet has been advocated for IBS with beneficial response in at least part of the patients (Halmos 2014). Many studies investigated the role of lactose in IBS. These studies were performed in the pre-Rome IV era and before standardized interpretation rules for Hydrogen breath testing (H2BT) were published (meta-analysis by Varju 2019). This meta-analysis indicated that subjective LI was more frequently reported by IBS patients, but also objectively more prevalent in IBS patients, when assessed by any test modality. However, the role of a LFD in IBS remains uncertain. This study aims to: * Determine if the diagnosis of LM by H2BT predicts the short-term and long-term response to a LFD in moderate to severe IBS as defined by Rome IV criteria; * Determine the changes in quality of life in response to a LFD in ROME IV IBS patients.

Milk for Diabetes Prevention

Individuals with lactase non-persistence (LNP; determined by a functional variant in the LCT gene \[rs4988235, GG genotype\]) are susceptible to lactose intolerance in adulthood due to deficiency of lactase, the enzyme which digests milk lactose sugars. However, many LNP individuals still drink ≥1 cup of milk daily. Recent analysis in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) found that consumption of 1 serving (cup) of milk/day was associated with \~30% lower risk of type 2 diabetes among LNP individuals, but not among individuals with lactase persistence (LP). This beneficial effect might be partially explained by favorable alterations in gut microbiota and related metabolites associated with higher milk consumption among LNP individuals. Based on these observational study findings, the investigator team proposes to conduct a randomized, controlled trial of lactose-containing vs. lactose-free milk in LNP individuals with pre-diabetes, to comprehensively investigate the effects of milk intake on the gut microbiome and glycemic outcomes.

Proper Dietary Management, Follow-up, and Lactase Enzyme Supplementation for Lactose Intolerance

Lactose intolerance (LI) is considered the clinical syndrome caused by lactose malabsorption (LM). It is possible to identify four causes of lactase deficiency defining four different types of LM: primary (genetic), secondary (acquired), congenital (alactasia), and developmental (in premature infants, so reversible). The aim of this protocol is to investigate through an anonymous online survey the knowledge of the Italian population on clinical, pathophysiological, diagnostic and therapeutic issues of lactose intolerance. Data collected will be divulgated through a publication for both people with IL and nutritionists, enriched with tables and flow charts, to improve the knowledge on lactose intolerance and to support people suffering from this condition. The results of this survey will guide subjects suspected of suffering from lactose intolerance towards a correct diagnosis and a better management.