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Interaction between the Herbal Preparation STW 5 and Human Intestinal Bacteria in Vitro
AGA Abstracts
SIBO, as H2S is bioactive and like methane appears to be important in predicting clinical symptoms such as diarrhea and fatigue. Table: Comparison of AUC 120 for hydrogen sulfide to symptoms during breath testing
1104 INTERACTION BETWEEN THE HERBAL PREPARATION STW 5 AND HUMAN INTESTINAL BACTERIA IN VITRO Christine Moissl-Eichinger, Koskinen Kaisa, Eva-Maria Pferschy-Wenzig, Alexandra Rossmann, Heba Abdel-Aziz, Rudolf Bauer STW 5 is a fixed herbal extract combination shown in several clinical studies to be effective in treating functional dyspepsia and irritable bowel syndrome (IBS). It seems to possess several mechanisms of action targeting diverse factors associated with functional GI-disorders. However, thus far its influence on intestinal microbiota has not been investigated. The preparation is a complex mixture of plant constituents, many of which are supposed to reach the distal gut after oral ingestion. There, they might interact with the intestinal microbial community, influencing microbial community composition. The impact of STW 5 on intestinal bacteria was studied by incubating lyophilized STW-5 dissolved in PBS buffer (0.45 and 2.25 mg/ml) with 10 % human fecal suspension under physiological conditions (anoxic, 37°C). Incubation experiments were performed for 24 h, and samples were taken 0.5 h (t= 1), 4 h (t=4) and 24 h (t=24) after STW 5 addition. Fecal suspension incubated with vehicle instead of STW 5 served as control. The composition of the microbial community at the different time points was analyzed by next generation sequencing (Illumina, MiSeq) of DNA extracted conventionally and of DNA from propidium monoazide-pretreated samples in order to mask the background DNA of dead cells. The focus of the analyses was on the 16S rRNA gene diversity of each sample, but also on the functional capability thereof (PiCRUST analyses). Sequencing experiments revealed that incubation with STW 5 caused significant changes in microbial community composition, while control samples remained quite stable over time (Fig.1). Comparison of t=1 samples with control samples revealed that the majority of these changes occurred already within the first 30 min, however, changes could be observed over the whole incubation period. Bacterial taxa that were most markedly enhanced belonged to the genus Enterococcus (Fig.2). Enterococci are Gram-positive bacteria that play an important role in digestion processes such as carbohydrate metabolism. Apart from Enterococcus species, Bacillus and Paenibacillus species, as well as Lactococcus representatives also increased over time. The strongest decrease could be observed in Clostridia representatives, in particular for Ruminococcaceae. Similarly affected were Bacteroidetes species. Enterococcus species ferment glucose without gas production, whereas Clostridia are supposed to produce hydrogen and CO2. Microbial functions involved in xenobiotics degradation were significantly enhanced. In conclusion, we can state that at least in vitro, addition of STW 5 has tremendous effect on intestinal microbial community composition and function, causing potentially less gas production and an increased well-being for the human host. If these findings can be confirmed in vivo, they would help to further explain the efficacy of STW 5 in IBS.
1103 GASTROINTESTINAL MOTILITY AND LUMINAL PH INFLUENCE IN VIVO DISSOLUTION AND SYSTEMIC ABSORPTION OF DRUG PRODUCT IN HUMAN GASTROINTESTINAL TRACT UNDER FED AND FASTED CONDITIONS Mark Koenigsknecht, Jason Baker, Ann F. Fioritto, Yasuhiro Tsume, Bo Wen, Joseph Dickens, Alex Yu, Jeffery Wysocki, Kerby Shedden, Barry Bleske, Allen Lee, William L. Hasler, Gordon Amidon, Duxin Sun Background: Gastrointestinal (GI) motility and luminal pH under fasted and fed states may influence systemic drug absorption and plasma drug concentration in addition to medication dose, dissolution, solubility, intestinal contents. Objective: To investigate the relationship among GI motility, pH, drug concentration in plasma and GI lumen of ibuprofen (IB) in different regions of the stomach and small bowel under fasted vs. fed status. A novel multilumen aspiration catheter was designed to determine luminal pH, gastric emptying, and motility in healthy humans under fasted vs. fed condition. Methods: Specialized manometry catheters with 4 aspiration ports were designed and orally inserted with fluoroscopic positioning of collection sites in the stomach, duodenum, and jejunum (N=27 procedures in 18 healthy humans). Subjects were randomized to fasting or fed (Pulmocare, Abbott Nutrition, 710 cal before drug dosing). GI fluid samples x 7 h and venous blood x 28 h post dosing were collected post IB dosing. GI fluid pH levels, and phases of the migrating motor complex (MMC) in the stomach and small bowel were recorded related to fed vs. fasted states. Immediate release IB (800 mg tablet) was ingested with non-absorbable phenol red marker in 250 mL of water. GI fluid and plasma ibuprofen concentrations were measured by LCMS/MS. Results: With an n=27 procedures in 18 healthy humans, gastric pH increased to near neutrality after feeding before generally decreasing to pH 2 at 7 h; higher pH levels related to greater gastric ibuprofen concentration levels but lower plasma levels during slow gastric emptying in the fed period. Analysis of fasting GI motility showed Cmax and Tmax generally occurring shortly after Phase III of MMCs (Figure 1). Additionally IB was detected immediately after ingestion in the stomach under fasting and fed conditions; overall gastric concentrations remained higher during the fed vs. fasting state until 7 h after oral dosing (Figure 2A). Duodenal and jejunal IB concentrations increased after gastric levels were detected and persisted x 7 h. IB plasma levels were higher during fasting vs. after feeding x 8 h and remained detectable x 28 h under both conditions (Figure 2B). Conclusions: This novel in vivo methodology involving time-dependent fluid sampling in several sites in the stomach and small intestine was employed to characterize GI motility, GI pH, drug dissolution, distribution in different regions of the upper GI tract in healthy human volunteers under fed and fasted states. Manometric studies of small bowel transit showed a correlation of GI motility with ibuprofen maximal concentration Cmax as well as Tmax. Taken together, these data show the importance of the fed vs. fasting state, GI motility, luminal pH, and systemic drug concentration and exposure, which may influence overall drug efficacy.
Fig. 1: PCoA plot on OTU level, showing the differences in microbiome composition of controls (circles) and samples (t=4: dark triangles, lower right corner; t=24: light triangles, upper right corner).
Fig. 2: Bubbleplot on operational taxonomic unit (OTU) level, showing the 20 most abundant OTUs, that were significantly increased or decreased in controls and samples with substance, respectively. Sample name explanation : Each sample name gives first the concentration in mg/30 ml fecal suspension (e.g. 13.5), followed by tube number (e.g. 16, indication of the treatment (PMA) and time point (e.g. t24): i.e., 13.5_16-PMA_t24 corresponds to tube number 16, with Iberogast concentration 13.5 mg/30 ml, PMA treated and drawn at time point 24 hours.
AGA Abstracts
S-206
SIBO, as H2S is bioactive and like methane appears to be important in predicting clinical symptoms such as diarrhea and fatigue. Table: Comparison of AUC 120 for hydrogen sulfide to symptoms during breath testing
1104 INTERACTION BETWEEN THE HERBAL PREPARATION STW 5 AND HUMAN INTESTINAL BACTERIA IN VITRO Christine Moissl-Eichinger, Koskinen Kaisa, Eva-Maria Pferschy-Wenzig, Alexandra Rossmann, Heba Abdel-Aziz, Rudolf Bauer STW 5 is a fixed herbal extract combination shown in several clinical studies to be effective in treating functional dyspepsia and irritable bowel syndrome (IBS). It seems to possess several mechanisms of action targeting diverse factors associated with functional GI-disorders. However, thus far its influence on intestinal microbiota has not been investigated. The preparation is a complex mixture of plant constituents, many of which are supposed to reach the distal gut after oral ingestion. There, they might interact with the intestinal microbial community, influencing microbial community composition. The impact of STW 5 on intestinal bacteria was studied by incubating lyophilized STW-5 dissolved in PBS buffer (0.45 and 2.25 mg/ml) with 10 % human fecal suspension under physiological conditions (anoxic, 37°C). Incubation experiments were performed for 24 h, and samples were taken 0.5 h (t= 1), 4 h (t=4) and 24 h (t=24) after STW 5 addition. Fecal suspension incubated with vehicle instead of STW 5 served as control. The composition of the microbial community at the different time points was analyzed by next generation sequencing (Illumina, MiSeq) of DNA extracted conventionally and of DNA from propidium monoazide-pretreated samples in order to mask the background DNA of dead cells. The focus of the analyses was on the 16S rRNA gene diversity of each sample, but also on the functional capability thereof (PiCRUST analyses). Sequencing experiments revealed that incubation with STW 5 caused significant changes in microbial community composition, while control samples remained quite stable over time (Fig.1). Comparison of t=1 samples with control samples revealed that the majority of these changes occurred already within the first 30 min, however, changes could be observed over the whole incubation period. Bacterial taxa that were most markedly enhanced belonged to the genus Enterococcus (Fig.2). Enterococci are Gram-positive bacteria that play an important role in digestion processes such as carbohydrate metabolism. Apart from Enterococcus species, Bacillus and Paenibacillus species, as well as Lactococcus representatives also increased over time. The strongest decrease could be observed in Clostridia representatives, in particular for Ruminococcaceae. Similarly affected were Bacteroidetes species. Enterococcus species ferment glucose without gas production, whereas Clostridia are supposed to produce hydrogen and CO2. Microbial functions involved in xenobiotics degradation were significantly enhanced. In conclusion, we can state that at least in vitro, addition of STW 5 has tremendous effect on intestinal microbial community composition and function, causing potentially less gas production and an increased well-being for the human host. If these findings can be confirmed in vivo, they would help to further explain the efficacy of STW 5 in IBS.
1103 GASTROINTESTINAL MOTILITY AND LUMINAL PH INFLUENCE IN VIVO DISSOLUTION AND SYSTEMIC ABSORPTION OF DRUG PRODUCT IN HUMAN GASTROINTESTINAL TRACT UNDER FED AND FASTED CONDITIONS Mark Koenigsknecht, Jason Baker, Ann F. Fioritto, Yasuhiro Tsume, Bo Wen, Joseph Dickens, Alex Yu, Jeffery Wysocki, Kerby Shedden, Barry Bleske, Allen Lee, William L. Hasler, Gordon Amidon, Duxin Sun Background: Gastrointestinal (GI) motility and luminal pH under fasted and fed states may influence systemic drug absorption and plasma drug concentration in addition to medication dose, dissolution, solubility, intestinal contents. Objective: To investigate the relationship among GI motility, pH, drug concentration in plasma and GI lumen of ibuprofen (IB) in different regions of the stomach and small bowel under fasted vs. fed status. A novel multilumen aspiration catheter was designed to determine luminal pH, gastric emptying, and motility in healthy humans under fasted vs. fed condition. Methods: Specialized manometry catheters with 4 aspiration ports were designed and orally inserted with fluoroscopic positioning of collection sites in the stomach, duodenum, and jejunum (N=27 procedures in 18 healthy humans). Subjects were randomized to fasting or fed (Pulmocare, Abbott Nutrition, 710 cal before drug dosing). GI fluid samples x 7 h and venous blood x 28 h post dosing were collected post IB dosing. GI fluid pH levels, and phases of the migrating motor complex (MMC) in the stomach and small bowel were recorded related to fed vs. fasted states. Immediate release IB (800 mg tablet) was ingested with non-absorbable phenol red marker in 250 mL of water. GI fluid and plasma ibuprofen concentrations were measured by LCMS/MS. Results: With an n=27 procedures in 18 healthy humans, gastric pH increased to near neutrality after feeding before generally decreasing to pH 2 at 7 h; higher pH levels related to greater gastric ibuprofen concentration levels but lower plasma levels during slow gastric emptying in the fed period. Analysis of fasting GI motility showed Cmax and Tmax generally occurring shortly after Phase III of MMCs (Figure 1). Additionally IB was detected immediately after ingestion in the stomach under fasting and fed conditions; overall gastric concentrations remained higher during the fed vs. fasting state until 7 h after oral dosing (Figure 2A). Duodenal and jejunal IB concentrations increased after gastric levels were detected and persisted x 7 h. IB plasma levels were higher during fasting vs. after feeding x 8 h and remained detectable x 28 h under both conditions (Figure 2B). Conclusions: This novel in vivo methodology involving time-dependent fluid sampling in several sites in the stomach and small intestine was employed to characterize GI motility, GI pH, drug dissolution, distribution in different regions of the upper GI tract in healthy human volunteers under fed and fasted states. Manometric studies of small bowel transit showed a correlation of GI motility with ibuprofen maximal concentration Cmax as well as Tmax. Taken together, these data show the importance of the fed vs. fasting state, GI motility, luminal pH, and systemic drug concentration and exposure, which may influence overall drug efficacy.
Fig. 1: PCoA plot on OTU level, showing the differences in microbiome composition of controls (circles) and samples (t=4: dark triangles, lower right corner; t=24: light triangles, upper right corner).
Fig. 2: Bubbleplot on operational taxonomic unit (OTU) level, showing the 20 most abundant OTUs, that were significantly increased or decreased in controls and samples with substance, respectively. Sample name explanation : Each sample name gives first the concentration in mg/30 ml fecal suspension (e.g. 13.5), followed by tube number (e.g. 16, indication of the treatment (PMA) and time point (e.g. t24): i.e., 13.5_16-PMA_t24 corresponds to tube number 16, with Iberogast concentration 13.5 mg/30 ml, PMA treated and drawn at time point 24 hours.
AGA Abstracts
S-206