Gut Lymphocyte Phenotype Changes After Parenteral Nutrition and Neuropeptide Administration

[Morphological predictors of water-electrolyte disorders in patients with preventive ileostomy after rectal resection for cancer]

OBJECTIVE

To analyze morphological changes in wall of functioning and non-functioning small intestine in patients with preventive ileostomy and to determine histological predictors of water-electrolyte disorders.

MATERIAL AND METHODS

We prospectively analyzed 57 patients >18 years old who underwent rectal resection with preventive ileostomy between January 2022 and November 2023. Anthropometric data included gender, age, body mass index, ECOG and ASA classes. Complications associated with large losses through ileostomy were water-electrolyte disorders, dehydration and acute renal failure with repeated hospitalization. Morphological analysis implied intraoperative full-layer biopsy of small intestine on anterior abdominal wall (ileostomy). Intraoperative biopsy of efferent and afferent loops was also carried out. Tissue samples were examined by light microscopy. We analyzed mean height of mucous membrane villi and depth of crypts, as well as their ratio. Fibrosis and swelling of submucosa were evaluated too. The results were analyzed in the SPSS Statistics 20 software.

RESULTS

Mean height of intestinal villi <465 microns (p=0.028), ratio of their height to crypt depth <4.38 (p=0.034) and submucosal fibrosis (p=0.031) significantly affected malabsorption and readmission of patients. The risk of readmission was 11.5 and 5.5 times higher in univariate analysis. Multivariate analysis revealed in-hospital dehydration with resumption of infusion therapy as a predictor of readmission (p=0.046).

CONCLUSION

Ileostomy is a certain stress for the patient's body. Not every patient is able for adaptation. One of the adaptation mechanisms is hypertrophy of mucous membrane villi involved in digestion. This mechanism is less pronounced in patients with repeated hospitalizations. Preoperative morphological examination of ileum mucosa may be an additional objective predictor of possible complications of preventive ileostomy.

The Pathology and Physiology of Ileostomy

An ileostomy is a surgery that is commonly performed to protect low pelvic anastomoses or prevent high-risk anastomotic leakages. However, various postoperative complications remain of major concern. After an ileostomy, the distal intestinal segment is left open for an extended period and is in a non-functional state. Consequently, the intestinal mucosa, smooth muscle, and microbiota undergo significant changes that are closely related to postoperative recovery and complications. A systematic description of these changes is necessary to understand the relationship among them and take more effective measures for postoperative intervention.

Partial enteral nutrition increases intestinal sIgA levels in mice undergoing parenteral nutrition in a dose-dependent manner

BACKGROUND AND AIMS

Partial enteral nutrition (PEN) protects parenteral nutrition (PN) induced gut mucosal immunity impairment. However, the gastrointestinal function of most patients with PN is too poor to tolerate full dosage of PEN and no guidelines recommend PEN dose. We aimed to identify an optimal PEN dose and to understand the protective mechanism.

METHODS

Mice were assigned to groups with total parenteral nutrition (TPN), total enteral nutrition (TEN), or various degrees of PEN with PN. Additionally, AS1517499 was used to inhibit STAT6. Five days after treatment, secretory immunoglobulin A (sIgA) levels of luminal washing fluid and JAK1-STAT6 signalling in ileum tissue of different groups were assessed.

RESULTS

We found that TPN lowered luminal sIgA and down-regulated pIgR, phosphorylated JAK1 and STAT6, IL-4 and IL-13 as well relative to TEN. Moreover, 40% EN were lowest dose that reversed these detrimental consequences of PN to an equivalent level as TEN. The rescue of pIgR and luminal sIgA expression was decreased when the JAK1-STAT6 pathway was inhibited.

CONCLUSION

We conclude that 40% EN is the optimal PEN dose that reverses PN-induced impairment of gut mucosal immunity. Additionally, we hypothesise that this benefit involves activation of the JAK1-STAT6 pathway.

Gastrointestinal immune and microbiome changes during parenteral nutrition

Parenteral nutrition (PN) is a lifesaving therapy that provides intravenous nutrition support to patients who cannot, or should not, feed via the gastrointestinal (GI) tract. Unfortunately, PN also carries certain risks related to infection and metabolic complications compared with enteral nutrition. In this review, an overview of PN and GI immune and microbiome changes is provided. PN impacts the gut-associated lymphoid tissue functions, especially adaptive immune cells, changes the intestinal epithelium and chemical secretions, and significantly alters the intestinal microbiome. Collectively, these changes functionally result in increased susceptibility to infectious and injurious challenge. Since PN remains necessary in large numbers of patients, the search to improve outcomes by stimulating GI immune function during PN remains of interest. This review closes by describing recent advances in using enteric nervous system neuropeptides or microbially derived products during PN, which may improve GI parameters by maintaining immunity and physiology.

Insights into bombesin receptors and ligands: Highlighting recent advances

This following article is written for Prof. Abba Kastin's Festschrift, to add to the tribute to his important role in the advancement of the role of peptides in physiological, as well as pathophysiological processes. There have been many advances during the 35 years of his prominent role in the Peptide field, not only as editor of the journal Peptides, but also as a scientific investigator and editor of two volumes of the Handbook of Biological Active Peptides [146,147]. Similar to the advances with many different peptides, during this 35 year period, there have been much progress made in the understanding of the pharmacology, cell biology and the role of (bombesin) Bn receptors and their ligands in various disease states, since the original isolation of bombesin from skin of the European frog Bombina bombina in 1970 [76]. This paper will briefly review some of these advances over the time period of Prof. Kastin 35 years in the peptide field concentrating on the advances since 2007 when many of the results from earlier studies were summarized [128,129]. It is appropriate to do this because there have been 280 articles published in Peptides during this time on bombesin-related peptides and it accounts for almost 5% of all publications. Furthermore, 22 Bn publications we have been involved in have been published in either Peptides [14,39,55,58,81,92,93,119,152,216,225,226,231,280,302,309,355,361,362] or in Prof. Kastin's Handbook of Biological Active Peptides [137,138,331].