MICROBIOTA INSIGHTS IN CLOSTRIDIUM DIFFICILE INFECTION AND INFLAMMATORY BOWEL DISEASE

Inflammatory bowel disease (IBD) is characterized by chronic intestinal inflammation that includes Crohn´s disease (CD) and ulcerative colitis (UC). Although the etiology is still unknown, some specific factors have been directly related to IBD, including genetic factors, abnormal intestinal immunity, and/or gut microbiota modifications. Recent findings highlight the primary role of the gut microbiota closely associated with a persistent inappropriate inflammatory response. This gut environment of dysbiosis in a susceptible IBD host can increasingly worsen and lead to colonization and infection with some opportunistic pathogens, especially Clostridium difficile. C. difficile is an intestinal pathogen considered the main cause of antibiotic-associated diarrhea and colitis and an important complication of IBD, which can trigger or worsen an IBD flare. Recent findings have highlighted the loss of bacterial cooperation in the gut ecosystem, as well as the pronounced intestinal dysbiosis, in patients suffering from IBD and concomitant C. difficile infection (CDI). The results of intestinal microbiota studies are still limited and often difficult to compare because of the variety of disease conditions. However, these data provide important clues regarding the main modifications and interrelations in the complicated gut ecosystem to better understand both diseases and to take advantage of the development of new therapeutic strategies. In this review, we analyze in depth the gut microbiota changes associated with both forms of IBD and CDI and their similarity with the dysbiosis that occurs in CDI. We also discuss the metabolic pathways that favor the proliferation or decrease in several important taxa directly related to the disease.

Different effect of laparoscopic Roux-en-Y gastric bypass and open biliopancreatic diversion of Scopinaro on serum PYY and ghrelin levels

BACKGROUND

The impact of bariatric surgery on levels of peptide YY (PYY) and ghrelin is still under discussion. We undertook a simultaneous evaluation of the serum changes in PYY and ghrelin depending on the specific type of bariatric surgery.

METHODS

Total PYY and ghrelin were analyzed in 29 healthy persons and in morbidly obese persons undergoing open biliopancreatic diversion (BPD) of Scopinaro (n = 38) or laparoscopic Roux-en-Y gastric bypass (RYGB; n = 13).

RESULTS

RYGB resulted in a significantly greater loss of weight and body mass index than BPD. Both RYGB and BPD were associated with a significant increase in PYY, significantly greater for BDP (p = 0.001). Ghrelin rose significantly after RYGB (p = 0.022) but not after BPD. After surgery, PYY correlated positively with weight (r = 0.416, p = 0.009). Ghrelin did not correlate significantly with any of the variables studied. Analysis of variance showed that only the type of surgery contributed significantly to explain the variances in the PYY (p = 0.002) and ghrelin (p = 0.018).

CONCLUSIONS

BPD results in a greater increase in PYY and a lower weight loss than RYGB. However, only RYGB was associated with a significant increase in ghrelin. The differing weight loss according to the type of bariatric surgery does not seem to be explained by changes arising in PYY and ghrelin.

Obesity and insulin resistance-related changes in the expression of lipogenic and lipolytic genes in morbidly obese subjects

BACKGROUND

The storage capacity of adipose tissue may be an important factor linking obesity, insulin resistance (IR), and associated morbidities. The aim of this study was to analyze the expression of lipogenic and lipolytic genes in adipose tissue and the influence of IR.

METHODS

We studied the mRNA expression of peroxisome proliferator-activated receptor-γ (PPARγ) and lipogenic and lipolytic enzymes in the visceral (VAT) and subcutaneous adipose tissue (SAT) from 23 morbidly obese patients (MO; 13 with low IR and ten with high IR) and from 15 healthy, lean controls.

RESULTS

In the VAT and SAT from the MO, we found an increased expression of PPARγ (p = 0.001 and p = 0.022, respectively), acyl-coenzyme A (CoA)/cholesterol acyltransferase (p < 0.001 and p < 0.001), aquaporin 7 (p < 0.001 and p = 0.003), and adipose triglyceride lipase (p < 0.001 and p < 0.001) and a reduced expression of acetyl-coenzyme A carboxylase (p = 0.004 and p < 0.001), independently of the state of IR. The expression of phosphoenolpyruvate carboxykinase and acyl-CoA synthetase, however, was significantly lower in the MO with high IR (p < 0.05). Glycerol kinase (p = 0.010), hormone-sensitive lipase (p < 0.001), and perilipin (p = 0.006) were only significantly increased in VAT. Acyl-CoA synthetase (p = 0.012) and fatty acid binding protein-4 (p = 0.003) were only significantly decreased in SAT. The expression of the genes studied was only greater in the SAT than the VAT in the controls.

CONCLUSION

Our results show an upregulation of genes facilitating triglyceride/fatty acid cycling and a reduction in the genes involved in de novo synthesis of fatty acids in morbid obesity. The expression of some of the genes studied seems to be related with the state of IR. VAT and SAT differ metabolically and also between controls and MO.

Genetic factors associated with alterations in liver function test results in adult hospitalized patients treated with parenteral nutrition: A substudy of a clinical trial

OBJECTIVES

The presence of phytosterols in vegetable-based lipid emulsions has been associated with alterations in the results of liver function tests (LFTs). Serum levels of phytosterols are under strict genetic control. T-allele carriers in rs41360247 and C-allele carriers in rs4245791 of ABCG8genes are associated with higher phytosterolemia. The objective of this study was to determine the association between these single-nucleotide polymorphisms (SNPs) and LFT result alterations in an adult hospitalized population treated with parenteral nutrition.

METHODS

This is a substudy of a previous clinical trial (EudraCT 2014-003597-17). It included adult hospitalized patients who had received at least 7 d of parenteral nutrition with 0.8 g/kg/d of an olive/soybean lipid emulsion, randomized 1:1 to receive the same olive/soybean emulsion or 100% fish oil at a dose of 0.4 g/kg/d for 7 d. Plasma phytosterols and their fractions, rs41360247 and rs4245791 of ABCG8 genes, and LFT were determined. Analyses of variance were performed to determine the association between the SNPs and LFT values, as well as total phytosterol values and their fractions. Simple linear regressions were performed to analyze LFT variations and the different interactions of the SNPs studied with phytosterols and their fractions. Interactions of the synergic variable plasma phytosterol and its fractions with SNPs allow us to study the interaction of the SNPs with phytosterols with a regression.

RESULTS

We included 19 participants. In the multivariate model, total phytosterols, sitosterol, and lanosterol were positively associated with increases in γ-glutamyltransferase. Significant increases with stigmasterol were associated with the T allele of rs41360247, whereas campesterol showed only a tendency to increase that was not significant. Increases in alkaline phosphatase were associated with T-rs41360247 independent of the presence of phytosterols. With stigmasterol, C-allele carriers of rs4245791 showed a tendency to increase, and also for sitosterol and lanosterol, although independent of the SNP analyzed. Increases in alanine aminotransferase were positively associated with total phytosterol and sitostanol, whereas lanosterol and stigmasterol were associated with the presence of the T allele of rs41360247.

CONCLUSIONS

With both SNPs rs41360247 and rs4245791, the alteration in parameters of liver function in adult patients with short-term parenteral nutrition is conditional.

Blood Phytosterol Concentration and Genetic Variant Associations in a Sample Population

The main objective of this study was to determine plasma levels of PS and to study SNVs rs41360247, rs4245791, rs4148217, and rs11887534 of ABCG8 and the r657152 SNV at the ABO blood group locus in a sample of a population treated at our hospital, and to determine whether these SNVs are related to plasma PS concentrations. The secondary objective was to establish the variables associated with plasma PS concentrations in adults. Participants completed a dietary habit questionnaire and a blood sample was collected to obtain the following variables: campesterol, sitosterol, sitostanol, lanosterol, stigmasterol, biochemical parameters, and the SNVs. In addition, biometric and demographic variables were also recorded. In the generalized linear model, cholesterol and age were positively associated with total PS levels, while BMI was negatively related. For rs4245791, homozygous T allele individuals showed a significantly lower campesterol concentration compared with C homozygotes, and the GG alleles of rs657152 had the lowest levels of campesterol compared with the other alleles of the SNV. Conclusions: The screening of certain SNVs could help prevent the increase in plasma PS and maybe PNALD in some patients. However, further studies on the determinants of plasma phytosterol concentrations are needed.