February 2011, Vol. 37, No. 1 , Pages 91-98 (doi:10.3109/1040841X.2010.536522
Lactic acid bacteria are a diverse group of bacteria that produce lactic acid as their major fermented product. Most of them are normal flora of human being and animals and produce myriad beneficial effects for human beings include, alleviation of lactose intolerance, diarrhea, peptic ulcer, stimulation of immune system, antiallergic effects, antifungal actions, preservation of food, and prevention of colon cancer. This review highlights the potential species of Lactic acid bacteria responsible for producing these effects. It has been concluded that lactic acid bacteria are highly beneficial microorganisms for human beings and are present abundantly in dairy products so their use should be promoted for good human health
Thursday
Cell adhesion and tissue response to hydroxyapatite nanocrystal-coated poly(L-lactic acid) fabric
Yanagida H, Okada M, Masuda M, Ueki M, Narama I, Kitao S, Koyama Y, Furuzono T, Takakuda K.
Department of Bioengineering, Advanced Medical Engineering Center, National Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka , Japan.
Cell adhesion and tissue response to poly(l-lactic acid) (PLLA) fabric coated with nanosized hydroxyapatite (HAp) crystals were studied. The HAp nanocrystals were prepared by the wet chemical process followed by calcination at 800 degrees C with an anti-sintering agent to prevent calcination-induced sintering.
After the PLLA fabric was hydrolyzed with an alkaline aqueous solution, the HAp nanocrystals were coated via ionic interaction between the calcium ions on the HAp and the carboxyl groups on the alkali-treated PLLA. The PLLA surface uniformly coated with the HAp nanocrystals was observed by scanning electron microscope. The ionic interaction between the HAp and the PLLA was estimated by FT-IR. Improved cell adhesion to the HAp nanocrystal-coated surface was demonstrated by in vitro testing using a mouse fibroblast cell line L929.
Furthermore, reduced inflammatory response to the HAp nanocrystal-coated PLLA fabric (as compared with a non-treated one) was confirmed by a subcutaneous implantation test with rats. Thus the HAp nanocrystal-coated PLLA developed has possible efficacy as an implant material in the fields of general and orthopedic surgery, and as a cell scaffold in tissue engineering
Department of Bioengineering, Advanced Medical Engineering Center, National Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka , Japan.
Cell adhesion and tissue response to poly(l-lactic acid) (PLLA) fabric coated with nanosized hydroxyapatite (HAp) crystals were studied. The HAp nanocrystals were prepared by the wet chemical process followed by calcination at 800 degrees C with an anti-sintering agent to prevent calcination-induced sintering.
After the PLLA fabric was hydrolyzed with an alkaline aqueous solution, the HAp nanocrystals were coated via ionic interaction between the calcium ions on the HAp and the carboxyl groups on the alkali-treated PLLA. The PLLA surface uniformly coated with the HAp nanocrystals was observed by scanning electron microscope. The ionic interaction between the HAp and the PLLA was estimated by FT-IR. Improved cell adhesion to the HAp nanocrystal-coated surface was demonstrated by in vitro testing using a mouse fibroblast cell line L929.
Furthermore, reduced inflammatory response to the HAp nanocrystal-coated PLLA fabric (as compared with a non-treated one) was confirmed by a subcutaneous implantation test with rats. Thus the HAp nanocrystal-coated PLLA developed has possible efficacy as an implant material in the fields of general and orthopedic surgery, and as a cell scaffold in tissue engineering
Monday
Lactic acid bacteria affect serum cholesterol levels, harmful fecal enzyme activity, and fecal water content
ABSTRACT: BACKGROUND: Lactic acid bacteria (LAB) are beneficial probiotic organisms that contribute to improved nutrition, microbial balance, and immuno-enhancement of the intestinal tract, as well as lower cholesterol. Although present in many foods, most trials have been in spreads or dairy products. Here we tested whether Bifidobacteria isolates could lower cholesterol, inhibit harmful enzyme activities, and control fecal water content.
METHODS: In vitro culture experiments were performed to evaluate the ability of Bifidobacterium spp. isolated from healthy Koreans (20~30 years old) to reduce cholesterol-levels in MRS broth containing polyoxyethanylcholesterol sebacate.
Animal experiments were performed to investigate the effects on lowering cholesterol, inhibiting harmful enzyme activities, and controlling fecal water content. For animal studies, 0.2 ml of the selected strain cultures (10;8~10;9 CFU/ml) were orally administered to SD rats (fed a high-cholesterol diet) every day for 2 weeks.
RESULTS: B. longum SPM1207 reduced serum total cholesterol and LDL levels significantly (p<0.05), and slightly increased serum HDL. B. longum SPM1207 also increased fecal LAB levels and fecal water content, and reduced body weight and harmful intestinal enzyme activities.
CONCLUSIONS: Daily consumption of B. longum SPM1207 can help in managing mild to moderate hypercholesterolemia, with potential to improve human health by helping to prevent colon cancer and constipation .
Lee DK, Jang S, Baek EH, Kim MJ, Lee KS, Shin HS, Chung MJ, Kim JE, Lee KO, Ha NJ.
METHODS: In vitro culture experiments were performed to evaluate the ability of Bifidobacterium spp. isolated from healthy Koreans (20~30 years old) to reduce cholesterol-levels in MRS broth containing polyoxyethanylcholesterol sebacate.
Animal experiments were performed to investigate the effects on lowering cholesterol, inhibiting harmful enzyme activities, and controlling fecal water content. For animal studies, 0.2 ml of the selected strain cultures (10;8~10;9 CFU/ml) were orally administered to SD rats (fed a high-cholesterol diet) every day for 2 weeks.
RESULTS: B. longum SPM1207 reduced serum total cholesterol and LDL levels significantly (p<0.05), and slightly increased serum HDL. B. longum SPM1207 also increased fecal LAB levels and fecal water content, and reduced body weight and harmful intestinal enzyme activities.
CONCLUSIONS: Daily consumption of B. longum SPM1207 can help in managing mild to moderate hypercholesterolemia, with potential to improve human health by helping to prevent colon cancer and constipation .
Lee DK, Jang S, Baek EH, Kim MJ, Lee KS, Shin HS, Chung MJ, Kim JE, Lee KO, Ha NJ.
Thursday
Stabilization of enzyme activity during the esterification of lactic acid in hydrophobic ethers and ketones as reaction media that are miscible with..
Lipase-catalyzed esterification of lactic acid has thus far achieved only limited success due to high acidity and polarity of lactic acid: acid inactivation of enzymes, and immiscibility of lactic acid with hydrophobic organic solvents that are commonly used for non-aqueous enzyme reactions. Herein, we investigated enzymatic esterification of lactic acid with ethanol by using hydrophobic ethers and ketones as reaction media. Both of the solvents are miscible with lactic acid, and have the basicity to suppress the acid inactivation of enzymes, as well as polar solvents. Nevertheless, these solvents would be less harmful to enzymes rather than polar solvents because of their high hydrophobicity. Using the ethers and ketones, ethyl lactate was successfully synthesized enzymatically even at higher lactic acid concentrations, and the enzyme activity was effectively stabilized even in repeated batch-wise reactions (2.0 M lactic acid, 4 weeks). This effect of some ethers and ketone to stabilize the enzyme was significantly higher than that of polar solvents in the presence of polar alcohols, the other substrate. In addition, more various kinds of lipase could esterify 1.0 M lactic acid, in the hydrophobic ether and ketone rather than those in hydrophobic solvents, polar solvents, and a solvent-free system.
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Tuesday
Stress upsets belly's balance
Some people find exams and other stressful life experiences coincide with gastrointestinal problems. New research has shown that their stomachs may be churning for a reason.
Swinburne psychology lecturer Dr Simon Knowles along with his colleague biotechnology researcher Dr Enzo Palombo and PhD student Elizabeth Nelson have studied the effect of stress on gastrointestinal flora .
“This is the first study to show that perceived stress affects the levels of good bacteria in the intestine,” Knowles said. “A reduction in these good bacteria is associated with gastrointestinal infections .”
The group studied the effect of perceived stress on salivary cortisol concentrations and lactic acid bacteria activity on 23 healthy undergraduate students.
Saliva and faecal samples were collected from the students at the beginning of the academic semester to obtain a low stress baseline and again during the first week of exams. The students also completed a series of questionnaires about their perceived levels of stress, what they ate and gastrointestinal symptoms.
Predictably, the students rated their perceived levels of stress as being greater during the exam period compared to the beginning of the semester. The study also found a corresponding lowering of faecal lactic acid bacteria levels during the high stress condition.
“This is evidence that stress can have a pervasive impact on an individual’s physiological as well as their psychological well-being,” said study author Dr Simon Knowles.
“Despite extensive research on the influence of stress on immune functioning and well-being, little is known about the impact of stress on gastrointestinal microflora. This is the first human study to show a link between stress and gut flora.
“This is significant because a reduction in good gut flora may contribute to the onset of gastrointestinal problems.”
Knowles suggests that the findings of this study could lead to intervention using cognitive behaviour therapy to help people to deal with the effects of stress.
The findings are detailed in an article published in the February 2008 issue of Biological Psychology.
Swinburne University
Swinburne psychology lecturer Dr Simon Knowles along with his colleague biotechnology researcher Dr Enzo Palombo and PhD student Elizabeth Nelson have studied the effect of stress on gastrointestinal flora .
“This is the first study to show that perceived stress affects the levels of good bacteria in the intestine,” Knowles said. “A reduction in these good bacteria is associated with gastrointestinal infections .”
The group studied the effect of perceived stress on salivary cortisol concentrations and lactic acid bacteria activity on 23 healthy undergraduate students.
Saliva and faecal samples were collected from the students at the beginning of the academic semester to obtain a low stress baseline and again during the first week of exams. The students also completed a series of questionnaires about their perceived levels of stress, what they ate and gastrointestinal symptoms.
Predictably, the students rated their perceived levels of stress as being greater during the exam period compared to the beginning of the semester. The study also found a corresponding lowering of faecal lactic acid bacteria levels during the high stress condition.
“This is evidence that stress can have a pervasive impact on an individual’s physiological as well as their psychological well-being,” said study author Dr Simon Knowles.
“Despite extensive research on the influence of stress on immune functioning and well-being, little is known about the impact of stress on gastrointestinal microflora. This is the first human study to show a link between stress and gut flora.
“This is significant because a reduction in good gut flora may contribute to the onset of gastrointestinal problems.”
Knowles suggests that the findings of this study could lead to intervention using cognitive behaviour therapy to help people to deal with the effects of stress.
The findings are detailed in an article published in the February 2008 issue of Biological Psychology.
Swinburne University
Wednesday
Lactic Acid and Sports Medicine
Plenty of research has swirled around about lactic acid in recent years and now scientists have debunked many of the myths that lactic impairs performance. In fact, now it is believed that lactic acid actually provides another fuel source for working muscles.
Lactic acid may still be behind the burning sensation during intense exercise but new research has confirmed that delayed onset muscle soreness is from the are microscopic tears and trauma to the muscles and inflammation.
Lactic acid was always seen as a by-product of metabolizing glucose for energy and a waste product that caused a burning sensation in the muscles. Now it is seen as another important fuel source in the body. Lactic acid is formed from glucose , and used by working muscles for energy. Now it is thought that muscle cells convert glucose or glycogen to lactic acid. Then Lactic acid is absorbed converted to a fuel by mitochondria in muscle cells.
By training at a high intensity, it is thought that athletes allow the Lactic acid to be more easily absorbed and converted to energy because the create additional proteins that do that job.
From Elizabeth Quinn ,
Lactic acid may still be behind the burning sensation during intense exercise but new research has confirmed that delayed onset muscle soreness is from the are microscopic tears and trauma to the muscles and inflammation.
Lactic acid was always seen as a by-product of metabolizing glucose for energy and a waste product that caused a burning sensation in the muscles. Now it is seen as another important fuel source in the body. Lactic acid is formed from glucose , and used by working muscles for energy. Now it is thought that muscle cells convert glucose or glycogen to lactic acid. Then Lactic acid is absorbed converted to a fuel by mitochondria in muscle cells.
By training at a high intensity, it is thought that athletes allow the Lactic acid to be more easily absorbed and converted to energy because the create additional proteins that do that job.
From Elizabeth Quinn ,
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