Intestinal Permeability, Prematurity
Conditions
Keywords
intestinal permeability, preterm infants, dual sugar test, intestinal microbiota
Brief summary
Necrotizing enterocolitis (NEC) is a life-threatening, gastrointestinal emergency characterized by increased intestinal permeability, affects approximately 7 to 10% of infants \<1500 g birthweight, and typically occurs within 7 to 14 days of birth. Mortality is as high as 30-50%. Prematurity is the greatest risk factor for the development of NEC due to the physiological immaturity of the gastrointestinal tract and altered or abnormal gut microbiota. Several studies have demonstrated that the initiation of an intense systemic and local inflammatory cascade leads to intestinal necrosis. The human intestine is lined by a single layer of cells exquisitely responsive to multiple stimuli and is populated by a complex climax community of microbial partners. Under normal circumstances, these intestinal cells form a tight but selective barrier to friends and foes: microbes and most environmental substances are held at bay, but nutrients are absorbed efficiently. Epithelial barrier integrity is itself dynamic and matures over time starting soon after birth, though the mechanisms regulating dynamic permeability are poorly understood. Low birth weight, prematurity, and early postnatal age are associated with a leaky gut. Although intestinal permeability is higher at birth in preterm than term infants, there is usually rapid maturation of the intestinal barrier over the first few days of life in both populations. The investigators hypothesize that increased levels of measures of intestinal permeability (urine lactulose/rhamnose (LA/Rh), and fecal alpha1- antitrypsin will identify infants at high risk for NEC and that intestinal probiotic strains will be associated with intestinal barrier maturation. The purpose of the study is to determine whether clinical factors in combination with non-invasive stool test such as antitrypsin (A1AT) and microbiota composition profile are associated with intestinal permeability determined by excretion of non-metabolized sugar probes in urine (LA/Rh ratio). These studies may lead to a non-invasive screening test to identify preterm infants at risk for NEC.
Detailed description
The proposed study will evaluate the intestinal permeability measured by the urinary La/Rh ratio at one timepoint between d7-10 of life in 200 preterm infants 24-32 weeks gestation in preparation for a future study of probiotics to improve intestinal permeability in this population. Primary Objective: To estimate mean and variance in IP measured by urinary Lactulose/Rhamnose ratio at 7-10d of life in neonates born between 24 and 32 weeks of gestational age. Secondary Objectives 1\) To assess stool microbiome characteristics in association with intestinal permeability in preterm infants measured by the urinary lactulose/rhamnose ratio.
Interventions
DRUGLactulose -rhamnose solution
Measurement of intestinal permeability by use of mon- digestible sugars known not to cross the intestinal barrier in normal healthy intestinal tissue
Sponsors
University of Maryland, Baltimore
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
SCREENING
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
No minimum to 4 Days
Healthy volunteers
No
Inclusion criteria
* \<5 days * Gestational age 24-32 weeks
Exclusion criteria
* Nonviable or planned withdrawal of care * Significant GI dysfunction (e.g. heme-positive stools, abdominal distension (girth \>2 cm baseline), or bilious emesis/aspirates. * Triplet or higher order multiple * Severe asphyxia * Lethal chromosome abnormalities * Cyanotic congenital heart disease * Intestinal atresia or perforation * Abdominal wall defects * Known galactosemia or other galactose intolerance
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Intestinal Permeability | 7-10 days postnatal | Intestinal Permeability measured by urinary excretion of orally administered lactulose/rhamnose (La/Rh ratio) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Stool Alpha-1 Antitrypsin | 7-10 days postnatal | Stool alpha-1 antitrypsin concentrations |
| Stool Microbiota Relative Abundance | 7-10 days postnatal | Relative abundance (%) Clostridiales species |
| Breastmilk Feeding Duration Prior to La/Rh Measurement | 7-10 days postnatal | Number of days breast milk feeding prior to La/Rh measurement between d7-10 days of age. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Percent Participants Exposed to Antibiotics Prior to La/Rh Measurement | 7-10 days postnatal | Percent of participants with antibiotic exposure prior to La/Rh measurement |
| Postnatal Age Full Feeds Reached | 0-100 days postnatal | Postnatal age when all nutrition is provided by enteral feeds |
| Occurrence of Necrotizing Enterocolitis | 0-28 days postnatal | Frequency of ≥ Stage 2 Necrotizing enterocolitis |
Countries
United States
Participant flow
Recruitment details
Infants born 24-32 weeks gestation were enrolled at a level IV Neonatal Intensive Care Unit at the University of Maryland Medical Center in the intestinal permeability study during 2 enrollment periods \[Cohort 1(April 15, 2013-October 15, 2014) (N=44)\] and \[Cohort 2 (October 15, 2018-June 11, 2021) (N=167)\].
Pre-assignment details
Parental consent was obtained for 214 infants, but parents of three infants withdrew consent prior to receipt of the sugar probe (lactulose/rhamnose) dose. Two infants died after consent, but before receiving the sugar probe dose. Seven infants were not dosed due to feeding intolerance (N=4), spontaneous intestinal perforation (N=2), transfer/discharge prior to dosing day (N=1). The remaining 201 enrolled infants received at least 1 dose of the sugar probe.
Participants by arm
| Arm | Count |
|---|---|
| Lactulose - Rhamnose Solution Preterm Infants age 24-32 weeks gestation
Lactulose -rhamnose solution: Measurement of intestinal permeability by use of mon- digestible sugars known not to cross the intestinal barrier in normal healthy intestinal tissue | 211 |
| Total | 211 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| IP in Preterm Infants: Cohort 1 | Death | 1 |
| IP in Preterm Infants: Cohort 2 | Death | 1 |
| IP in Preterm Infants: Cohort 2 | did not receive sugar probe dose | 8 |
Baseline characteristics
| Characteristic | Lactulose - Rhamnose Solution |
|---|---|
| Age, Categorical <=18 years | 211 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 0 Participants |
| Age, Continuous | 1.93 days STANDARD_DEVIATION 1.08 |
| Age, Customized Gestational age Gestational age 24wk 0d-28wk6d | 63 Participants |
| Age, Customized Gestational age Gestational age 29wk 0 d- 32 wk 6d | 148 Participants |
| Birthweight <1000 gm BW | 53 Participants |
| Birthweight ≥1000 gm BW | 158 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 6 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 204 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 1 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 9 Participants |
| Race (NIH/OMB) Black or African American | 123 Participants |
| Race (NIH/OMB) More than one race | 2 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 5 Participants |
| Race (NIH/OMB) White | 72 Participants |
| Region of Enrollment United States | 211 participants |
| Sex: Female, Male Female | 100 Participants |
| Sex: Female, Male Male | 111 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 2 / 211 |
| other Total, other adverse events | 32 / 211 |
| serious Total, serious adverse events | 22 / 211 |
Outcome results
Primary
Intestinal Permeability
Intestinal Permeability measured by urinary excretion of orally administered lactulose/rhamnose (La/Rh ratio)
Time frame: 7-10 days postnatal
Population: Study participants who had lactulose/rhamnose sugar solution administered between 7-10 days postnatal age and urine collected over 4 hours that was measured for lactulose/rhamnose concentration by HPLC.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Gestational Age <29 wk | Intestinal Permeability | 0.0731 ratio | Standard Deviation 0.0076 |
| Gestational Age ≥29 Weeks | Intestinal Permeability | 0.0720 ratio | Standard Deviation 0.0078 |
Comparison: We hypothesized that intestinal permeability as measured by urinary lactulose/rhamnose ratio would be higher in the lower gestational age (\<29 weeks) compared to the more mature infants (≥29 weeks gestation) at postnatal age 7-10 days.p-value: 0.932t-test, 2 sided
Secondary
Breastmilk Feeding Duration Prior to La/Rh Measurement
Number of days breast milk feeding prior to La/Rh measurement between d7-10 days of age.
Time frame: 7-10 days postnatal
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Gestational Age <29 wk | Breastmilk Feeding Duration Prior to La/Rh Measurement | 7.02 days | Standard Deviation 1.38 |
| Gestational Age ≥29 Weeks | Breastmilk Feeding Duration Prior to La/Rh Measurement | 6.1 days | Standard Deviation 1.96 |
Comparison: We hypothesized that infants with normal barrier function (La/Rh ratio ≤0.05) would have been fed breastmilk for longer duration than infants with impaired barrier function (La/Rh\>0.05).p-value: 0.0023t-test, 2 sided
Secondary
Stool Alpha-1 Antitrypsin
Stool alpha-1 antitrypsin concentrations
Time frame: 7-10 days postnatal
Population: Infants at 7-10 days of age in the first cohort who had stool collected on the same day as urinary IP measurement that was assayed by ELISA for A1AT concentration.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Gestational Age <29 wk | Stool Alpha-1 Antitrypsin | 359.5 µg/ml | Standard Deviation 137 |
| Gestational Age ≥29 Weeks | Stool Alpha-1 Antitrypsin | 1285.3 µg/ml | Standard Deviation 802.3 |
Comparison: We hypothesized that stool A1AT would be higher in infants with high IP as measured by urinary La/Rh compared to those with low IP.p-value: 0.316t-test, 2 sided
Secondary
Stool Microbiota Relative Abundance
Relative abundance (%) Clostridiales species
Time frame: 7-10 days postnatal
Population: Infants who had both urinary La/Rh ratio and stool Clostridiales abundance determined
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Gestational Age <29 wk | Stool Microbiota Relative Abundance | 6.52 percentage of Clostridiales in stool |
| Gestational Age ≥29 Weeks | Stool Microbiota Relative Abundance | 0.07 percentage of Clostridiales in stool |
p-value: 0.011Bayesian goodness of fit
Other Pre-specified
Occurrence of Necrotizing Enterocolitis
Frequency of ≥ Stage 2 Necrotizing enterocolitis
Time frame: 0-28 days postnatal
Population: Infants who had urinary La/Rh measured between 7-10 days of age (total N=189)
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Gestational Age <29 wk | Occurrence of Necrotizing Enterocolitis | 0 Participants |
| Gestational Age ≥29 Weeks | Occurrence of Necrotizing Enterocolitis | 0 Participants |
p-value: 1Chi-squared
Other Pre-specified
Percent Participants Exposed to Antibiotics Prior to La/Rh Measurement
Percent of participants with antibiotic exposure prior to La/Rh measurement
Time frame: 7-10 days postnatal
Population: Study participants who had urinary La/Rh ratio measured on postnatal day 7-10.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Gestational Age <29 wk | Percent Participants Exposed to Antibiotics Prior to La/Rh Measurement | 79 Participants |
| Gestational Age ≥29 Weeks | Percent Participants Exposed to Antibiotics Prior to La/Rh Measurement | 67 Participants |
p-value: 0.461Chi-squared
Other Pre-specified
Postnatal Age Full Feeds Reached
Postnatal age when all nutrition is provided by enteral feeds
Time frame: 0-100 days postnatal
Population: Study participants who had urinary La/Rh ratio measured between 7-10 days of age.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Gestational Age <29 wk | Postnatal Age Full Feeds Reached | 11.46 days | Standard Deviation 5.04 |
| Gestational Age ≥29 Weeks | Postnatal Age Full Feeds Reached | 22.02 days | Standard Deviation 45.5 |
Comparison: We hypothesized that infants with impaired barrier function as measured by high urinary La/Rh (\>0.05) ratio at 7-10 days of age would require longer time to reach full enteral feedings than infants with normal barrier function (La/Rh≤0.05)p-value: 0.019t-test, 2 sided