Feeding Formula Eliminates the Necessity of Bacterial Dysbiosis and Induces Inflammation and Injury in the Paneth Cell Disruption Murine NEC Model in an Osmolality-Dependent Manner

Abstract

Necrotizing enterocolitis (NEC) remains a significant cause of morbidity and mortality in preterm infants. Formula feeding is a risk factor for NEC and osmolality, which is increased by the fortification that is required for adequate growth of the infant, has been suggested as a potential cause. Our laboratory has shown that Paneth cell disruption followed by induction of dysbiosis can induce NEC-like pathology in the absence of feeds. We hypothesized adding formula feeds to the model would exacerbate intestinal injury and inflammation in an osmolality-dependent manner. NEC-like injury was induced in 14–16 day-old C57Bl/6J mice by Paneth cell disruption with dithizone or diphtheria toxin, followed by feeding rodent milk substitute with varying osmolality (250–1491 mOsm/kg H2O). Animal weight, serum cytokines and osmolality, small intestinal injury, and cecal microbial composition were quantified. Paneth cell-disrupted mice fed formula had significant NEC scores compared to controls and no longer required induction of bacterial dysbiosis. Significant increases in serum inflammatory markers, small intestinal damage, and overall mortality were osmolality-dependent and not related to microbial changes. Overall, formula feeding in combination with Paneth cell disruption induced NEC-like injury in an osmolality-dependent manner, emphasizing the importance of vigilance in designing preterm infant feeds.

Immunoglobulin A, an Active Liaison for Host-Microbiota Homeostasis

“…In a Paneth cell disruption NEC rodent model, the addition of formula feeding exacerbated intestinal injury independent of gut microbial dysbiosis [152]. This result emphasized the caution needed for preterm infant feeding.…”

Bifidobacterium longum Subspecies infantis Strain EVC001 Decreases Neonatal Murine Necrotizing Enterocolitis

“…To remove the potential confounding impact of K. pneumoniae use in the Paneth cell disruption model, we also employed our recently described RMS formula-Paneth cell model [40]. In brief, P14-16 mice were given an intraperitoneal injection of 75 µg/kg of dithizone (Sigma-Aldrich, St. Louis, MO, USA) dissolved in 25 mM lithium carbonate or an equivalent volume of lithium carbonate alone as a vehicle control.…”

“…Ileal intestinal injury scoring was performed by a single blinded investigator as previously described [38][39][40]42,43]. In brief, the distal 1/3 of the intestine just before the cecum was harvested and then fixed in 10% buffered formalin, embedded in paraffin, and then sectioned at five µm thickness.…”

Evidence‐Based Practices Reduce Necrotizing Enterocolitis and Improve Nutrition Outcomes in Very Low‐Birth‐Weight Infants

“…15 A recent animal study showed increased inflammation and intestinal injury in mice fed on hyperosmolar feeds compared with controls. 16 We have studied the change in osmolality when medications and fortifiers were added to milk feeds and water. The freezing-point depression method was used to derive a neat osmolality measure of medications and diluents (water, breast milk, fortified breast milk, and formula milk) separately and then in combination.…”

“…The American Academy of Pediatrics has recommended an osmolality not exceeding 450 mOsm/kg for preterm milk feeds to curtail the risk of NEC 15 . A recent animal study showed increased inflammation and intestinal injury in mice fed on hyperosmolar feeds compared with controls 16 . We have studied the change in osmolality when medications and fortifiers were added to milk feeds and water.…”