Effects of Coffee on the Gastro-Intestinal Tract: A Narrative Review and Literature Update.

The objective of the present research was to review the state of the art on the consequences of drinking coffee at the different levels of the gastrointestinal tract. At some steps of the digestive process, the effects of coffee consumption seem rather clear. This is the case for the stimulation of gastric acid secretion, the stimulation of biliary and pancreatic secretion, the reduction of gallstone risk, the stimulation of colic motility, and changes in the composition of gut microbiota. Other aspects are still controversial, such as the possibility for coffee to affect gastro-esophageal reflux, peptic ulcers, and intestinal inflammatory diseases. This review also includes a brief summary on the lack of association between coffee consumption and cancer of the different digestive organs, and points to the powerful protective effect of coffee against the risk of hepatocellular carcinoma. This review reports the available evidence on different topics and identifies the areas that would most benefit from additional studies.

Changes in saliva analytes in equine acute abdominal disease: a sialochemistry approach.

BACKGROUND: The biochemical components of saliva can change in certain pathologies in horses, for example in acute abdominal disease. The aim of this study was (1) to evaluate if a panel of biochemical analytes usually used in serum can be measured in saliva of horses and (2) to study the possible changes of these biochemical analytes in saliva of horses affected by acute abdominal disease. A panel of 23 analytes was analytically validated in saliva of horses and possible changes in these analytes in a pilot study with six healthy horses and six horses with acute abdominal disease were evaluated. The analytes with significant changes were then evaluated in a larger population of 20 healthy and 37 diseased horses. RESULTS: Seven analytes showed significant increases in the pilot study which were confirmed in the larger population. The analytes which showed significant changes, and their median fold increase and significance shown in the larger population were salivary γ-glutamyl transferase (gGT, 2.3 fold, P = 0.001), creatine kinase (CK, 6.2 fold, P < 0.001), urea (2.3 fold, P = 0.001), total bilirubin (2.6 fold, P < 0.001), total proteins (3.2 fold, P < 0.001), phosphorus (P, 4.5 fold, P < 0.001) and alpha-amylase (sAA, 8.5 fold, P < 0.001). Total proteins, P and sAA showed sensitivities higher than 70% at their optimal cut-off points and a specificity of 100% in differentiating between healthy horses and those with acute abdominal disease. CONCLUSIONS: A panel of 23 biochemical analytes can be measured in saliva of horses, where gGT, CK, urea, total bilirubin, total protein, P and sAA levels are raised in horses with acute abdominal disease.

Inhibitory effect of black tea, lemon juice, and other beverages on salivary and pancreatic amylases: What impact on bread starch digestion? A dynamic in vitro study.

Certain food properties (ex.: pH, polyphenolic composition) can inhibitdigestive amylases and thereby slow down starch digestion. Our aim was twofold. (1) To determine the impact of21 beverages and condiments (coffees, teas, wines, vinegars and lemon juice)on salivary and pancreatic amylolysis: inhibition ranged from 10% to 100%in our experimental conditions. (2) To investigate the effect of one black tea and lemon juice (selected for their strong inhibitory capacity) on starch hydrolysis during dynamicoro-gastro-intestinal digestion of bread. Compared to water (control), the effect of black tea was limited to a ≈20% reduction of released oligosaccharides during the intestinal phase. Lemon juice had a remarkable effect, completely interrupting gastric amylolysis by salivary amylase via a preliminary acidification of gastric contents. These results provide a strong biochemical rationale for the development of dietary strategies to improve the glycaemic impact of starch-rich meals which could be tested in vivo.

Enhancement in the Catalytic Activity of Human Salivary Aldehyde Dehydrogenase by Alliin from Garlic: Implications in Aldehyde Toxicity and Oral Health.

BACKGROUND: Lower human salivary aldehyde dehydrogenase (hsALDH) activity increases the risk of aldehyde mediated pathogenesis including oral cancer. Alliin, the bioactive compound of garlic, exhibits many beneficial health effects. OBJECTIVE: To study the effect of alliin on hsALDH activity. METHODS: Enzyme kinetics was performed to study the effect of alliin on the activity of hsALDH. Different biophysical techniques were employed for structural and binding studies. Docking analysis was done to predict the binding region and the type of binding forces. RESULTS: Alliin enhanced the dehydrogenase activity of the enzyme. It slightly reduced the Km and significantly enhanced the Vmax value. At 1 µM alliin concentration, the initial reaction rate increased by about two times. Further, it enhanced the hsALDH esterase activity. Biophysical studies indicated a strong complex formation between the enzyme and alliin (binding constant, Kb: 2.35 ± 0.14 x 103 M-1). It changes the secondary structure of hsALDH. Molecular docking study indicated that alliin interacts to the enzyme near the substrate binding region involving some active site residues that are evolutionary conserved. There was a slight increase in the nucleophilicity of active site cysteine in the presence of alliin. Ligand efficiency metrics values indicate that alliin is an efficient ligand for the enzyme. CONCLUSION: Alliin activates the catalytic activity of the enzyme. Hence, consumption of alliincontaining garlic preparations or alliin supplements and use of alliin in pure form may lower aldehyde related pathogenesis including oral carcinogenesis.

An Open-Label Uncontrolled Trial of the Efficacy and Safety of a Hug with Singing and Rocking for Promotion of Relaxation in Pediatric Patients with Severe Motor and Intellectual Disabilities: Study Protocol.

Children with severe motor and intellectual disabilities (SMID) are continually exposed to stress due to their need to receive daily care. In particular, chronic physical and acute mental stress derived from daily medical care due to unstable health status are issues specific to SMID children. Therefore, it is important to approach these issues for the maintenance of their lives and quality of life. Seventeen children with a SMIDmedical care dependent group (SMID-MCDG) score of 25 or more will be enrolled in this study. Intervention by a hug while singing and rocking will be performed once a week for 24 weeks. The practitioner will sing, and slowly rock the child back and forth. Primary endpoint is high-frequency component of heart rate variability by frequency analysis. Secondary endpoints are low-frequency/high-frequency components of heart rate variability by frequency analysis, activity of salivary amylase, the incidence of adverse events, and changes in appearance. Frequency analysis of heart beat changes and salivary amylase activity are used as physiological indexes for assessing response to being held while singing and rocking. In this study, we will examine the efficacy and safety of hugging while singing and rocking as a practice of Ryouiku to promote relaxation in SMID-MCDG children.

Dietary effects of Sideritis scardica "mountain tea" on human in vivo activities of xenobiotic metabolizing enzymes in healthy subjects.

Sideritis scardica(S. scardica) is an endemic plant of the Balkan Peninsula traditionally used as herbal tea for inflammation and gastric disorders. Aqueous herbal extracts may affect the activity of Phase I and II enzymes involved in xenobiotic metabolism. The purpose of the present study was to determine whether S. scardica decoction alters the activity of CYP1A2, CYP2A6, XO, NAT2 and UGT1A1/1A6 enzymes in humans. Fourteen healthy subjects consumed S. scardica decoction for six days. Enzyme phenotyping was assessed in saliva and urine using caffeine and paracetamol metabolite ratios as follows: CYP1A2: 17X/137X (saliva) and (AFMU+1U+1X)/17U, CYP2A6: 17U/(17U + 17X), XO: 1U/(1U+1X), NAT2: AFMU/(AFMU+1U+1X) and UGT1A1/1A6: glucuronidated/total paracetamol (urine). After S. scardica intake, CYP1A2 index was reduced by ∼16% and ∼8% in saliva (before: 0.54 ±â€¯0.18, after: 0.46 ±â€¯0.09; p = 0.08) and urine (before: 3.59 ±â€¯0.52, after: 3.67 ±â€¯0.78; p = 0.12), respectively. CYP2A6 index was significantly reduced only in males (before: 0.76 ±â€¯0.08, after: 0.67 ±â€¯0.07; p = 0.004), suggesting sexual dimorphism in CYP2A6 inhibition. There was no effect of Sideritis scardica treatment on XO, NAT2 or UGT1A1/1A6 indices. Usual consumption of the aerial parts of S. scardica decoction is unlikely to result in herb-drug interactions involving the enzymes studied, with the exception of potential herb-CYP2A6 substrate interaction in males.

Effect of lactoferrin on taste and smell abnormalities induced by chemotherapy: a proteome analysis.

Cancer patients receiving chemotherapy often experience taste and smell abnormalities (TSA). To date, the underlying molecular mechanisms of this frequent side-effect have not been determined and effective treatments are not available. This study assessed the feasibility of lactoferrin (LF) supplementation as a treatment for TSA and investigate the related mechanisms through salivary proteome analysis. Nineteen cancer patients with established TSA following chemotherapy administration were enrolled in this study. Cancer patients and additional 12 healthy subjects took LF supplements, 3 tablets per day (250 mg per tablet), for 30 days. Saliva was collected at three timepoints: baseline, 30-day LF supplementation, and 30-day post-LF supplementation. Patient's TSA level, salivary proteome, and salivary minerals at each LF treatment stage were analyzed. High TSA level was associated with high concentration of salivary Fe and loss of critical salivary immune proteins. LF supplementation significantly decreased the concentration of salivary Fe (P = 0.025), increased the abundance (P < 0.05) of salivary α-amylase and Zn-α-2-GP, and led to an overall increase of expression (≥2-fold changes) of immune proteins including immunoglobulin heavy chain, annexin A1, and proteinase inhibitor. Abundance of α-amylase and SPLUNC2 were further increased (P < 0.05) at 30-day post-LF supplementation in cancer patients. At the same time, total TSA score was significantly reduced (P < 0.001) in chemotherapy patients. This study demonstrated the feasibility of developing lactoferrin supplementation as a treatment to reduce TSA caused by chemotherapy and improve cancer patient's oral immunity.

Sour cherry extract inhibits human salivary α-amylase and growth of Streptococcus mutans (a pilot clinical study).

The purpose of this study was to determine whether cherry extract has any effect on salivary α-amylase activity (sAA) or on the level of Streptococcus mutans in human saliva. 70 patients (45 females and 25 males) in three age groups (22 children, 25 young adults, and 23 adults) were examined. All participants completed a questionnaire to obtain information on their oral health behaviour and life style. Clinical examination was performed to record the number of decayed, missing and filled teeth (DMF-T). Saliva samples were collected for the measurement of sAA and the salivary S. mutans level before and after chewing a gum with or without cherry extract. Statistical evaluation of data was performed. S. mutans and the sAA level of unstimulated saliva samples did not depend on either age or gender. The basal sAA value of adult patients was in linear correlation with the dental caries status. Habitual chewing-gum use decreased the resting sAA and the mean of DMF-T. The number of S. mutans cells was significantly lower in the resting saliva of allergic patients. The applied mechanical and gustatory stimuli by chewing gum resulted in higher sAA and S. mutans levels and a slow decrease of values was observed in the control group for the next 30 min. Thereafter, sAA and S. mutans levels decreased earlier in the presence of sour cherry extract than those of control cases. Chewing gum with sour cherry extract may be useful for the prevention of dental caries.

Simulated Digestion and Fermentation in Vitro by Human Gut Microbiota of Polysaccharides from Bee Collected Pollen of Chinese Wolfberry.

Digestion and fermentation in vitro of polysaccharides from bee collected pollen of Chinese wolfberry (WBPPS) were investigated in the present study. It was found that WBPPS mainly consisted of mannose, ribose, rhamnose, galacturonic acid, glucose, galactose, xylose, and arabinose in a molar ratio of 0.38:0.09:0.17:0.64:0.22:0.67:0.08:1.03, respectively. WBPPS was not affected by human saliva. The fraction A (molecular weight 1340 kDa) of WBPPS was not broken down in simulated gastric and small intestinal juices, while the small fraction B (molecular weight 523 kDa) of WBPPS was degraded. Moreover, fermentation in vitro revealed that WBPPS could significantly enhance the production of short-chain fatty acids and modulate gut microbiota composition via increasing the relative abundances of genera Prevotella, Dialister, Megamonas, Faecalibacterium, and Alloprevotella and decreasing the numbers of genera Bacteroides, Clostridium XlVa, Parabacteroides, Escherichia/Shigella, Phascolarctobacterium, Parasutterella, Clostridium sensu stricto, and Fusobacterium.

Intraspecific differences in plant defense induction by fall armyworm strains.

The underlying adaptive mechanisms by which insect strains are associated with specific plants are largely unknown. In this study, we investigated the role of herbivore-induced defenses in the host plant association of fall armyworm (Spodoptera frugiperda) strains. We tested the expression of herbivore-induced defense-related genes and the activity of plant-defensive proteins in maize and Bermuda grass upon feeding by fall armyworm strains. The rice strain caterpillars induced greater accumulation of proteinase inhibitors in maize than the corn strain caterpillars. In Bermuda grass, feeding by the corn strain suppressed induction of trypsin inhibitor activity whereas the rice strain induced greater activity levels. Differences in elicitation of these plant defenses by the two strains seems to be due to differences in the activity levels of the salivary enzyme phospholipase C. The levels of plant defense responses were negatively correlated with caterpillar growth, indicating a fitness effect. Our results indicate that specific elicitors in the saliva of fall armyworm stains trigger differential levels of plant defense responses that affect caterpillar growth and thus may influence host plant associations in field conditions. The composition and secretion of plant defense elicitors may have a strong influence in the host plant association of insect herbivores.

Reactivation of peroxidase activity in human saliva samples by polyphenols.

OBJECTIVES: The enzyme lactoperoxidase (LPO), which is released into several body fluids like saliva, is an essential part to maintain the oral bacterial homeostasis by catalysing the oxidation of thiocyanate (SCN-) to hypo-thiocyanite (-OSCN). The formation of unreactive redox intermediates (like Compound II) leads to a decreased pseudo-halogenating enzyme activity, which is associated with a higher risk for oral infections. According to former studies with bovine LPO selected flavonoids were tested in respect to their potential to reactivate the enzymatic activity in a more physiological, human salivary system. DESIGN: Saliva samples from healthy donors were collected and characterized by using several gel staining methods and immunoblotting. Afterwards kinetic measurements were performed by applying the TNB-assay to evaluate the pseudo-halogenating salivary peroxidase (SAPX) activity. The measurements were performed in the presence of excess H2O2 to simulate pro-inflammatory conditions. Moreover selected flavonoids or an ethanolic extract of Tormentillae rhizoma were applied to test their regenerating effect on the LPO-derived -OSCN production. RESULTS: Despite the complex protein composition of the collected saliva samples, an SAPX-derived pseudo-halogenating activity could be identified. The -OSCN regenerating effects of the tested polyphenols were completely comparable to previous in vitro experiments with bovine LPO. Thus, we could show that phenolic substances are suitable to regenerate the peroxidase activity in human saliva samples after H2O2-induced inactivation. CONCLUSION: The studies provide new insights into the effect of pharmaceutical relevant polyphenols on salivary peroxidase activity and thus, suggest this enzyme as a new target for the prevention and therapy of oral inflammatory diseases.

Reducing of salivary α-amylase inhibition by using bovine serum albumin and calcium chloride for forensic saliva screening.

Inhibiting salivary α-amylase is a critical issue of forensic saliva identification using the catalytic method. This study aims to identify human α-amylase inhibitors in forensic saliva screening by using a blue starch amylase test and to measure the extent of enzyme inhibition. Thus, in order to demonstrate the presence of inhibitors, we prepared positively charged metal ion sources or chelators that were mixed into the saliva stains. The results of this study show that ferric chloride (FeCl3), magnesium chloride, ethylenediaminetetraacetic acid, and citric acid significantly decrease the α-amylase activity of saliva stains. We also verified this approach using blood, a magnesium-containing liquid supplement, and two citric acid-containing soft drinks that were contaminated with saliva stains as forensic mock samples; these samples also showed a significant reduction in salivary α-amylase activity. To establish an inhibitor-resistant blue starch amylase test, we applied bovine serum albumin (BSA) and calcium chloride (CaCl2) to the reaction system. The results show that salivary α-amylase inhibition of the forensic mock samples occurred under normal test conditions (i.e., 300ng/µL BSA, 0mM CaCl2), and that inhibition was significantly relieved under the BSA+CaCl2 conditions (i.e., 1000ng/µL BSA, 5mM CaCl2). Therefore, the results of this study demonstrate that both BSA and CaCl2 can be utilized as reaction stabilizers in forensic saliva screening.

Volatile Components of the Essential Oil of Artemisia montana and Their Sedative Effects.

The sedative effects of volatile components in the essential oil of Artemisia montana ("Yomogi") were investigated and measured using gas chromatography-mass spectrometry (GC-MS). Major components identified included 1,8-cineol, camphor, borneol, α-piperitone, and caryophyllene oxide. Among them, 1,8-cineol exhibited the highest flavor dilution (FD) value in an aroma extract dilution analysis (AEDA), followed by borneol, o-cymene, ß-thujone, and bornyl acetate. The sedative effects of yomogi oil aroma were evaluated by sensory testing, analysis of salivary α-amylase activity, and measurement of relative fluctuation of oxygenated hemoglobin concentration in the brain using near-infrared spectroscopy (NIRS). All results indicated the stress-reducing effects of the essential oil following nasal exposure, and according to the NIRS analysis, 1,8-cineol is likely responsible for the sedative effects of yomogi oil.

Evaluation of salivary catalase, vitamin C, and alpha-amylase in smokers and non-smokers: a retrospective cohort study.

BACKGROUND: Saliva and its defence systems such as antioxidants and minerals are very important in the pathogenesis of different diseases. Cigarette smoking has many destructive effects. Oxidative stresses play an important role in the side effects of smoking. This study assessed the effect of cigarette smoking on salivary levels of catalase, vitamin C, and α-amylase. METHODS: This retrospective cohort study was carried out in Hamadan, Iran, on 510 subjects; 259 subjects were smokers (the exposed group) and 251 were non-smokers (the unexposed group). Five microliters of unstimulated saliva was collected by spitting method. Catalase, vitamin C, and α-amylase salivary levels were determined by spectrophotometric assay. Data were analyzed with t-test using STATA 12. RESULTS: Vitamin C level in smokers was significantly lower than that in non-smokers. The salivary catalase levels were lower and α-amylase levels were higher in smokers, but the differences were not statistically significant (P = 0.416 and P = 0.265, respectively). Smokers were younger than non-smokers. CONCLUSION: Smoking resulted in a change in salivary antioxidant levels. Changes in antioxidant levels can influence the deleterious effects of smoking on oral mucosa; it might also indicate systemic changes and changes in the serum levels of oxidative agents. Further studies are necessary to understand the mechanisms and real effects of smoking, to determine the benefits of supplementary antioxidants for treatment and to reduce the dangerous side effects of smoking.

In vitro digestibility of highly concentrated methylcellulose O/W emulsions: rheological and structural changes.

The changes in structure during the digestion of highly concentrated methyl cellulose (MC) O/W emulsions and of hydrated MC were investigated. The effect of human saliva and in vitro stomach digestion was attributed to a dilution effect, rather than to pH or pepsin activity. After in vitro intestine incubation, a decrease in viscoelasticity and an increase in fat globule size were observed. The fat released after the digestion of the MC emulsion was 49.8% of the initial fat, indicating the existence of a big physical impediment. In comparison with an O/W whey protein emulsion with fat content equal to the fat released during the MC emulsion digestion, a 12% reduction in free fatty acid formation was found, which indicates that the decrease in fat bioaccessibility in the MC emulsion should be attributed not only to a physical effect against fat release but also to a further impediment related to the fat digestion process. Fat released quantification informs about the physical retention of fat in the emulsion matrix structure. Enzymes may not act if fat is not released and solubilized. Free fatty acid quantification is the real indicator of fat digestion, but contrary to the total fat released, it is affected by a wide variety of enzymatic factors, which should be considered for the correct comparison of systems of different properties, for example systems where the amount of fat release during the digestion may be different or initially unknown.

Oral hygiene grade and quality of life in children with chemotherapy-related oral mucositis: a randomized study on the impact of a fluoride toothpaste with salivary enzymes, essential oils, proteins and colostrum extract versus a fluoride toothpaste without menthol.

AIM: The aim of this study was to assess the impact of the use of a fluoride toothpaste (Bioxtra® , Biopharm, Milan, Italy) with salivary enzymes, essential oils, proteins and colostrum extract versus a fluoride toothpaste without menthol on the oral hygiene grade and on the quality of life (QoL) of children with oral mucositis (OM) grade 1 or 2 receiving chemotherapy for Acute Lymphoblastic Leukaemia (ALL). METHODS: Patients between 6 and 14 years with OM were randomly assigned to two groups, group A (Bioxtra® toothpaste) and group B (fluoride toothpaste without menthol). The patients were instructed to brush their teeth at least twice a day using a soft toothbrush with a small head. Oral hygiene grade was assessed using the simplified oral hygiene index (OHI-s); quality of life was assessed using the short form of the Oral Health Impact Profile (OHIP-14) questionnaires. The patients were evaluated on day 1(diagnosis of OM-T0) and on day 8 (T1). Statistical analysis was performed. RESULTS: A total of 64 patients were enrolled. A significant difference (P < 0.001) between the mean of the OHI-s in group A (0.9 ± 1.2) and in group B (1.5 ± 1.3) was found; the overall OHIP-14 scores were not associated with the use of one or the other toothpaste (P = 0.33). CONCLUSIONS: Although the use of Bioxtra® toothpaste does not affect the QoL of children undergoing chemotherapy, it may be recommended as clinically effective in improving the oral hygiene grade.

Variability in emotional responsiveness and coping style during active avoidance as a window onto psychological vulnerability to stress.

Individual differences in coping styles are associated with psychological vulnerability to stress. Recent animal research suggests that coping styles reflect trade-offs between proactive and reactive threat responses during active avoidance paradigms, with proactive responses associated with better stress tolerance. Based on these preclinical findings, we developed a novel instructed active avoidance paradigm to characterize patterns of proactive and reactive responses using behavioral, motoric, and autonomic measures in humans. Analyses revealed significant inter-individual variability not only in the magnitude of general emotional responsiveness but also the likelihood to specifically express proactive or reactive responses. In men but not women, individual differences in general emotional responsiveness were linked to increased trait anxiety while proactive coping style was linked to increased trait aggression. These patterns are consistent with preclinical findings and suggest that instructed active avoidance paradigms may be useful in assessing psychological vulnerability to stress using objective behavioral measures.

[Effects of Atractylodis Macrocephale Rhizoma processed by different methods on salivary amylase and D-xylose excretion rate in rats].

To observe the effects of Atractylodis Macrocephale Rhizoma processed by different methods (sulfur-fumigation, different temperatures baking and microwave sterilization) on salivary amylase and D-xylose excretion rate in spleen deficiency rats. The rats were divided into blank control group, rhubarb-induced spleen deficiency model control group, and Atractylodis Macrocephale Rhizoma experimental groups processed with different methods. Amylase colorimetric method was used to determine the activities of salivary amylase and D-xylose excretion rate was measured with O-benzylamine method. Then the correlation of salivary amylase activity and D-xylose excretion rate in urinary was analyzed. As compared with blank control group, Atractylodis Macrocephale Rhizoma baked at 100,110 ℃ can increase the unit content of rat salivary amylase and D-xylose excretion rate, with a significant difference (P<0.05). As compared with the model group, Atractylodis Macrocephale Rhizoma baked at 70 ℃ and Atractylodis Macrocephale Rhizoma with microwave treatment had stronger effects than the others, with statistically significant differences (P<0.01). Atractylodis Macrocephale Rhizoma could improve D-xylose absorption function and salivary amylase activity in spleen deficiency rats. In addition, D-xylose excretion rate in urine was positively correlated with salivary amylase activity. Atractylodis Macrocephale Rhizoma processed with different temperatures baking and microwave sterilization had little impact on salivary amylase activity and D-xylose excretion rate in urine of spleen deficiency rats, while sulfur fumigation had great effects on the above two indexes.

Influence of a Suggestive Placebo Intervention on Psychobiological Responses to Social Stress: A Randomized Controlled Trial.

We tested the hypothesis that a suggestive placebo intervention can reduce the subjective and neurobiological stress response to psychosocial stress. Fifty-four healthy male subjects with elevated levels of trait anxiety were randomly assigned in a 4:4:1 fashion to receive either no treatment (n = 24), a placebo pill (n = 24), or a herbal drug (n = 6) before undergoing a stress test. We repeatedly measured psychological variables as well as salivary cortisol, alpha-amylase, and heart rate variability prior to and following the stress test. The stressor increased subjective stress and anxiety, salivary cortisol, and alpha-amylase, and decreased heart rate variability (all P < .001). However, no significant differences between subjects receiving placebo or no treatment were found. Subjects receiving placebo showed increased wakefulness during the stress test compared with no-treatment controls (P < .001). Thus, the suggestive placebo intervention increased alertness, but modulated neither subjective stress and anxiety nor the physiological response to psychosocial stress.

Alteration of consciousness via diverse photo-acoustic stimulatory patterns. Phenomenology and effect on salivary flow rate, alpha-amylase and total protein levels.

Long-term photo-acoustic stimulation is used for the induction of altered states of consciousness for both therapeutic and experimental purposes. Long-term photo-acoustic stimulation also leads to changes in the composition of saliva which have a key contribution to the efficiency of this technique in easing mucosal symptoms of oral psychosomatic patients. The aim of this study is to find out whether there is any cumulative effect of repeated stimulation and whether there are any detectable differences between diverse stimulatory patterns of long lasting photo-acoustic stimulation on the phenomenology of the appearing trance state and on salivary secretion. There was significant cumulative effect in relation with the appearance of day dreaming as phenomenological parameter, and in relation with protein output and amylase/protein ratio as salivary parameter. Pattern specific effect was detectable in relation with salivary flow rate only. Although our results clearly indicate the existence of certain cumulative and stimulation-pattern specific effects of repeated photo-acoustic stimulation, the absolute values of all these effects were relatively small in this study. Therefore, in spite of their theoretical importance there are no direct clinical consequences of these findings. However, our data do not exclude at all the possibility that repeated stimulation with other stimulatory parameters may lead to more pronounced effects. Further studies are needed to make clear conclusion in this respect.